Now he is predicting that the Magpies, for whom Ba has scored 16 goals so far this season, could suffer a similar fate if they do not address the issue of the much-publicised release-clause in his contract.

Speaking to the website www.westhamtillidie.com, Sullivan said: “I’m told he’s got a £7m get-out at Newcastle and he gets half the money over that.

“They keep denying it, but I think you’ll see in the summer he will leave Newcastle, or he’ll get a monstrous rise to stay there.

“If they get about £4m, half will go to him, so if they sell him for £7m, they’ll only net about three because they paid his agent £2m to get him out of here.

“Getting £3m is not bad, but for a player of his quality, it’s not fantastic.”

Ba joined the Hammers from German club Hoffenheim on a three-and-a-half-year deal in January last year after failing a medical at Stoke, with the Londoners agreeing to pay an appearance-related fee after an initial down-payment of €500,000.

The club negotiated a clause under which his wages would be reduced by half if they were relegated, and he in turn secured an agreement that he could leave if they dropped out of the top flight.

Sullivan said: “It’s one of those mistakes that happen, but it’s probably one of the worst mistakes I have ever made in my life.

“It just didn’t enter our heads. It didn’t enter anybody’s head that he’d score enough goals that we’d want to give him £40k a week and his old club £15-20k an appearance and we’d still be relegated.

“In reality, that’s exactly what happened. The agent just threw it in at the last minute.

“He said, ’Obviously if his salary is cut by 50%, you’ve got to let him walk’. We thought, ’Okay, if we get relegated, do we really want a £40k-a-week striker in the Championship?’.

“Well, we would have because he was devastating. If he was with us now and his knee had held up – because remember, he did have a very, very bad knee – I think we’d be 15 points clear, I really do.

“He’d be cutting through those defences. You live and you learn.”

Ba, who scored seven times in 12 league appearances for the Hammers, has been a huge hit on Tyneside.

After a slow start to his career in the north-east – manager Alan Pardew put that down to the effects of his observance of Ramadan – he announced himself in style with a hat-trick against Blackburn in September and has never looked back since.

He departed for the African Nations Cup early last month having added a further 12 goals to his account and marked his return after a disastrous campaign for his country in Equatorial Guinea and Gabon with the opener in a 2-1 victory over Aston Villa on February 5.

However in the meantime, talk of the release-clause had led to speculation that one of the Premier League’s big boys could come calling, and that will inevitably resurface as the summer transfer window approaches.

Newcastle were relaxed at the time and with Ba having insisted since his return that he is happy at the club, which signed international team-mate Papiss Cisse last month, they will hope they can fend off any interest.

However, it would be no surprise if there was an attempt to renegotiate his contract in an effort to take the uncertainty out of the situation.