SKY SPORTS last night tried to extinguish the sexism row engulfing the broadcaster by sacking the pundit Andy Gray for “unacceptable and offensive behaviour” after new evidence came to light of him making suggestive remarks to a female co-presenter.

The broadcaster was last night under pressure to explain why Gray had been dismissed while his co-presenter Richard Keys and the touchline reporter Andy Burton were still employed, despite similar offences.

Sky said Gray had been sacked after new evidence relating to an off-air incident that took place in December 2010 “came to light after Andy Gray had already been subjected to disciplinary action for his comments of January 22nd”.

The fresh evidence emerged after a video was posted on YouTube that showed him asking fellow presenter Charlotte Jackson to “tuck this in for me love” as he gestured towards his trousers during a commercial break.

“Andy Gray’s contract has been terminated for unacceptable behaviour. After issuing a warning yesterday we have no hesitation in taking this action after becoming aware of new information today,” said Sky Sports’ managing director, Barney Francis.

Gray, a central character on Sky who helped make the broadcaster into one of the most powerful forces in sport on the back of its multi-billion pound Premier League rights deals, was last night facing the prospect of seeing his career unravel.

Betfair, the online betting exchange which pays Gray a substantial sum to appear in its advertising, said earlier in the day that, while it would not tolerate sexism, it had “no plans to change” its relationship with Gray. But following his sacking Betfair said: “In light of the latest developments we are reviewing the situation.”

Gray was hauled off air on Monday after he and Keys were caught on tape making derogatory comments about female assistant referee Sian Massey during the Wolves versus Liverpool match.

Speculation last night centred on who leaked the offending clips, first to the Mail On Sundaythen to Sky News showing Gray discussing Massey's looks with Burton before the match at Molineux and then to YouTube showing the incident with Jackson.

Insiders said last night the most likely explanation was disgruntled colleagues had systematically leaked the footage to seal Gray’s fate. In one of several intriguing subplots Sky News has diligently covered the story – and was the first outlet to show the exchange between Gray and Burton – while Sky Sports News largely ignored it.

Gray is also one of several public figures taking legal action against the News of the World, another part of Rupert Murdoch's media empire, over the ongoing phone hacking allegations.

While Massey was last night stood down from her planned engagement to run the line for Crewe’s match with Bradford for fear it would place her at the centre of a media circus, employment lawyers warned Gray could have a case for unfair dismissal.

“The decision to sack Andy Gray leaves Sky with a real risk of being sued for unfair dismissal. Should Gray pursue a claim, the burden will be on Sky to show that it dismissed Gray for a fair reason,” said employment lawyer Andrew Haywood. “That the two other individuals involved, Richard Keys and Andy Burton, seem to have avoided dismissal despite similar allegations raises a number of difficult questions for Sky.”

Keys, whose apology to Massey on Sunday was accepted by the 25-year-old assistant referee, is not expected to return to the screen until next week at the earliest. Burton was yesterday dropped as touchline reporter for tonight’s League Cup semi-final between Birmingham City and West Ham.

Sky Sports: Their statement

SKY SPORTS yesterday terminated its contract with Andy Gray. The decision, which is effective immediately, was made in response to new evidence of unacceptable and offensive behaviour.

The new evidence, relating to an off-air incident that took place in December 2010, came to light after Andy Gray had already been subjected to disciplinary action for his comments of January 22nd, 2011.

Barney Francis, managing director of Sky Sports, commented: "Andy Gray's contract has been terminated for unacceptable behaviour. After issuing a warning yesterday, we have no hesitation in taking this action after becoming aware of new information today."