Federal agents seized the cell phone of John Eastman , an attorney who advised former President Donald Trump in his bid to overturn the results of the 2020 presidential election, Eastman said in a court filing on Monday.

Eastman filed a lawsuit asking the Justice Department to return his property and destroy any records it had obtained after FBI agents in New Mexico stopped him as he was leaving a restaurant last week. The investigators had a warrant and seized his iPhone, the filing says, and agents were able to access his email accounts.

The lawyer said in the filing the agents forced him to unlock the device.

By its very breadth, the warrant intrudes on significant privacy interests, both of [Eastman] and of others whose communications with him are accessible on the seized cell phone, his attorneys wrote in the filing, obtained by The Hill.

Eastman was a key figure in developing a plan that would have seen Vice President Mike Pence delay or block certification fo the 2020 Electoral College results, and his work has become a central focus of the House select committee investigating the Jan. 6, 2021, insurrection at the U.S. Capitol. Pence refused to go along with the scheme.