NBC News and MSNBC say they have terminated contracts with US political journalist Mark Halperin following allegations of sexual harassment.

The allegations relate to Mr Halperin’s work at ABC more than a decade ago.

Penguin Press has cancelled a book co-authored by Mr Halperin about the 2016 election, and HBO has cancelled a planned TV adaptation of the book.

The Showtime network said Mr Halperin would not return to political programme The Circus, which will be renamed.

At least 12 women have come forward to report that Mr Halperin harassed or assaulted them during his stint as political director at ABC News.

Mr Halperin issued a statement on Twitter on Friday, apologising for his actions and admitting that he “Caused fear and anxiety for women who were only seeking to do their jobs”.

A raft of sexual harassment allegations against media and entertainment industry figures has emerged in recent weeks, sparked by accusations against Hollywood mogul Harvey Weinstein.