Eccleston quits new 'Doctor Who' series

The newest incarnation of revived sci-fi series Doctor Who is running into yet another roadblock: the resignation of its star.

Christopher Eccleston, the ninth actor to portray the time-travelling titular hero, has announced he is quitting the show over concerns he might get typecast. His last episode is expected to air in the U.K. in December.

"The audience's response for the new Doctor Who has been incredible and I am really proud to be part of it and I hope viewers continue to enjoy the series," Eccleston said in a statement. He added, however, that he had found filming the series gruelling.

The BBC-produced series, relaunched after 16 years, drew almost 10 million U.K. viewers for its debut episode last Saturday.

According to the BBC, several replacements for Eccleston are being discussed for a second 13-episode season of the new series. Leading candidates include David Tennant, who recently starred as the famed Casanova in a BBC TV series, comedian Eddie Izzard and actor Bill Nighy, seen most recently in films Love Actually, Shaun of the Dead and Underworld.

• RELATED: CBC-TV: Doctor Who

Doctor Who debuts in Canada next Tuesday on CBC-TV. So far, no American broadcaster has picked up the popular British series, which began in 1963.

• RELATED STORY: New 'Doctor Who' leaks on the net

Previously, producers had a setback when a review copy of the highly anticipated and highly promoted series was posted on the internet in early March. Sources at the BBC pointed to the CBC, which denied the allegation and investigated the leak. Both now say that a third party company in Canada was to blame and that the person responsible has been fired.