In trying to flee the war, this Ukrainian dad ended up in a Russian prison and his kids in Moscow

In some of Evgeny Mezhevoy's darkest moments, like when he was interrogated and crammed into an overcrowded detention centre in Russian-occupied Donetsk, the single father imagined himself speaking to his three children, who he says were torn away from him at a checkpoint while trying to escape the Russian assault on Mariupol.

"I talked to each one of them. I calmed them down," Mezhevoy told CBC News in an interview from their two-bedroom apartment in Riga, Latvia, at the end of November.

"I said I would come for them and I'm still alive."

Those inner conversations helped sustain himthroughweeks of fear and uncertainty, until the family could be reunited again.

Mezhevoy, 39, was separated from his children in April, when Russian soldierson the outskirts ofMariupolnoticed a Ukrainian military ID in his passport, which he received when he wasemployed as a mechanic.

He eventually ended up in prison, while the children were put on a plane to Moscow with the promise of attending a camp.

"I did not want to go anywhere. Iknew this was no summer camp of any kind,"said Mezhevoy's 13-year-old son,Matvey.

Matvey and his two sisters, Sviatoslava, 9, and Alexandra, 7, are amongmore than 13,000 children Ukraine says wereforcibly deported to Russia after itlaunched itsinvasion on Feb. 24.

Ukraine has accused Russia of stealing some of its youngest and most vulnerable. Russia, on the other hand,is painting itself as the saviour of forgotten orphans.

Many of the children reportedly sent to Russia came from orphanages in the occupied territories, but child welfare experts say the vast majority aren't actually orphans and were previously placed in care because their parents were unable to look after them.

Other children, like the Mezhevoys,ended up in Russia after being forcibly separated from their families by soldiers at checkpoints,or through the chaos and violence of war.

Life in war-torn Mariupol

Ukrainian officials have urged the UN and the G20 to get involved. International organizations say there is a great need for an independent body to verify Ukraine's data and work with both countries tolocatethe children and connectthem with relatives who have scattered over the past nine months.

After Russia launched its invasion, Mezhevoy and his children spent weeks huddled in basements in Mariupol, trying to stay alive as Russian soldiers lay siege to the southern port city.

Near the end of March, they moved into a bunker in one of the city's hospitals, where they sheltered with more than 100 people.By then, Mezehevoy says the city was ruins and dead bodies lay on the streets.The only time they would venture outside was to fetch water.

One day in early April, Mezhevoy says Russian soldiers told everyone staying in the hospitalbunker that they would have to leave. While some chose to stay, Mezhevoy packed up his children and boarded a minibus to a checkpoint.

It was there that soldiers saw his passport and eventually led him away from the children.

"It's terrifying not knowing where your kids are," he said."The unknown is the scariest."

Over the next month and half, he was interrogated about his links to the Ukrainian military and asked whether he was affiliated with the Azov regiment, a unit that is part of Ukraine's National Guard, and which Russia accuses of Nazi sympathies.

Mezhevoy said at times thedetained men had to sleep standing up because the rooms were so crowded, and the unbearable heat meant most stripped down to their underwear.

He said he was punched a few times, when guards didn't like how he answered questions. He told CBC that some of the other men had dark bruises all over their bodies.

Sent to Moscow

In May, Mezhevoy was transferred to the Olenikva prisonin the Donetsk region, which eventually became a holding cell for Ukrainian prisoners of war. It came under attackin July;Ukraine and Russia blamed each other for the strikes, whichkilled dozens.

Mezhevoy had been released by then.He said that on May 26, the guards there suddenlytold him he could go, at which point he started making calls to track down his children.

He discovered thaton the day after he was released, theyhad been put on a plane to Moscow, after spending weeks at different locations in Donetsk, including a cultural centreand a hospital.

Mezhevoy's son, Matvey, says thatduring their separation,he had no idea where their father was. At one point, the children put up a homemade poster saying they were looking for their dad.

When they flewto Moscow,Matveysays they were on a plane with dozens of other children.

They were all sent to what the Mezhevoy family described as aheavily guarded site just outside of Moscow. The camp was named Polyana.

The Mezhevoy children told CBCthat they didn't want to be there, but they didn't describe any mistreatment, and said they spent a lot of time relaxing.

They said officials there organizedactivities for them, including a dance party, which the children took a video of and shared with CBC.

Matvey said that during their stay, they were givena number of medical examinations, including blood tests,as well as pills thathe believed were vitamins.

Even though the separation was difficult, Mezhevoythought the children were better off staying where they were, until he could find a job and safe place to take them to.

Mezhevoy says Russianofficials told him that thechildren would be brought back to Donetsk in a few weeks.But by mid-June, those plans changed, as intense fighting was still underway.

On June 16, Mezhevoyreceived an urgent call from Matvey. He told his fatherthat a social worker said the camp was ending, and that if theirfather didn't pick them up soon,they were going to be temporarily taken to an orphanage or placed with a foster family.

Mezhevoy blames the Russian government for taking Ukrainian children but he doesn't blame ordinary Russians.

WATCH | Putin deals with growing criticism of Ukraine invasion:

Vladimir Putin works to fend off mounting criticism of Ukraine invasion

2 years ago

Duration 2:16

Russian President Vladimir Putin met with a hand-picked gathering of military mothers in an attempt to fend off mounting criticism of his latest troop deployment in Ukraine.

It was Russian volunteers that helped him quickly travel from eastern Ukraine to Moscow to pick up his children. These volunteerseven paid for part of his journey.

After proving his identity and filling out some paperwork, Mezhevoy was escorted into the campfor atear-filled reunion with his children. Ithad beentwomonths since he had last seenthem at the Mariupol checkpoint.

The family then travelled to Riga, Latvia, where they have settled for now.

Russia welcomes 'orphans'

On Russian state television and social media, officials have posted multiple videos of smiling Ukrainian children getting off planes in Moscow and being greeted by Russian foster families holding balloon animals.

In May, President Vladimir Putin signed a decree simplifying the process of obtaining Russian citizenship for Ukrainian orphans and children without parental care.

On July 5, when thefirst group of children became citizens, Russia's children's rights commissioner, Maria Lvova-Belova, posted a highly produced video of the ceremony.

"Now that the children have become Russian citizens, temporary guardianship can become permanent," she wrote on her Telegram account.

Lvova- Belova, who has been sanctioned by Canada and other Western nations, did not respond to CBC's request for an interview.

This fall, she announced that she herself had adopted a teenage son from Mariupol. She later described in a state television documentary that themoment she met him, she just felt "he belongs to me."

Lvova-Belovahas also posted images of children with severe health conditions being removed from an orphanage inthe southeasterncity ofKhersonwhen it was stilloccupied by Russia forces.

Ukrainian officials are now collecting those kinds of images as evidence.

"It is very hard to particularly know where a child is, especially when we are talking about deportation ... by Russian military forces," said Maryna Lypovetska, who is with the Ukrainian NGO Magnolia.The organization looks for missing children, and has already received more than 2,600 appeals this year more than it had during its previous two decades of existence.

Lypovetska, who spoke to CBCby video call from Kyiv, said Magnolia gets a lot of messages aboutchildren who went missing in Russian-occupied areas.

When Lypovetska seessocial media posts about Russian families adopting Ukrainian orphans, she says she's infuriated,as many of the children aren't really orphans. Ukraine also banned all international adoptions during the war.

Even if they have no parents, shesays the kids might still have other relatives.

"They have rights. They're Ukrainian citizens," she said."They have a right to reunite with their own families."

Call for independent investigation

According to AagjeIeven, secretary general for Brussels-based Missing Children Europe, Russia's actions so farsuggest a plan to remove the children from Ukraine in order to take away their nationality and identity. She describes what is happening not as "deportation" but "forced displacement."

"I think there is quite a lot of work to still be done in terms of proving what is actually going on," said Ieven, who says an independent party needs to verify the number of children sent to Russia, and then look at each individual to see whether they have parents or other family members.

Ieven says "data and that level of proof" would help in "demonstrating that this is actually a war crime, rather than just Russia saving children."

Mezhovoysays a prosecutor from Ukraine has spoken with him about his case, and the children have met with a psychologist.CBC reached out to the office of Ukraine's Prosecutor General, but didn't receive a response.

Mezhevoy believes his kids are handling the stress of the past year well, but they do still get scared of loud noises and when they hear a plane.

Sitting inside the family's apartment, his daughter Sviatoslava says she wasworried that if her father didn't getto Moscowin time, they would be adopted by a Russian family permanently.

"Nothing is short-term," she proclaimed while sitting on a top bunk, a reference to Russian claims of temporary guardianship.

Mezhevoy shakes his head when he is asked about the thousands of Ukrainian children who have apparently been sent to Russia.

"It is wrong," he said."I don't understand are there really so few homeless children in Russia, that they are taking ours?"

WATCH | Ukraine accuses Russia of taking thousands of children:

Russia accused of taking thousands of Ukrainian children

2 years ago

Duration 7:01

The Ukrainian government says roughly 13,000 children, some with living family members, have been illegally taken to Russia since the war started. Ukraine says its a war crime, and Russia claims its saving forgotten orphans.

With files from Corinne Seminoff andIrene Shcherbakova