The London club, seeking to appease their supporters over the loss of Anton Ferdinand and McCartney to Sunderland and the subsequent resignation of manager Alan Curbishley, released a statement saying McCartney asked to leave.

McCartney, currently on international duty with Northern Ireland, spoke to reporters yesterday saying that was nonsense.

But the Hammers hit back with an official statement saying they had the documentation.

The club said: "Having previously declared their interest, Sunderland approached West Ham United at the end of last week with a renewed offer to sign the player.

"Both McCartney and his agent were made aware of this development.

"However, as was demonstrated by the rejection of a previous bid and with the subsequent agreement of a new five-year contract, West Ham United had no intention of selling McCartney.

Following this offer from Sunderland, McCartney handed in a signed written transfer request on Monday, 1 September which stated "due to private, family reasons I wish to accept the offer to move back to Sunderland AFC".

West Ham United are astonished by the claims made subsequently by the player that there was no written request to leave, with McCartney having also repeatedly spoken of his desire to return to Sunderland to both the manager and senior club officials.

On Sunday , a senior club official wrote to McCartney stating: "No one wants to sell. If you are happy to stay, great, it ends here. I thought you were unhappy and wanted to go."

The player then restated his desire to leave before handing in the written transfer request on Monday.

McCartney tells a different story and believes he has been made a scapegoat following Curbishley exit in disgust at the club's transfer policy.

He said: "I have seen on the West Ham website I handed in a written transfer request.

"I never did anything of the sort. Probably the board at West Ham are trying to cover their tracks.

"I did propose that for family reasons I would like to move back north. But the manager said 'no' I wasn't leaving and just to concentrate on West Ham.

"I was happy to stay. That was on the Friday and I played my part in the Blackburn game on the Saturday.

"The thought of leaving was finished as far as I was concerned but then something changed. I got on an indication on Sunday that I could be on my way.

"These are strange times at West Ham and no one really knows what is going on at boardroom level.

"The board have not been behind Alan Curbishley since the start of the season.

"It was a difficult time for him - they did not trust him with any money to spend.

"I cannot understand how a manager can be under so much pressure. He saved us from relegation and we finished 10th last year. This season has been the club's best start for years.

"I loved my time under Alan Curbishley, got on well with him and never had any problems with him. West Ham was the place to be and I loved my two years there."

While mystery might surround McCartney's Upton Park departure, he is determined to put that behind him and focus on his new Sunderland career.

"Maybe I can help get Sunderland to a higher level," he said. "That is the challenge and one I am looking forward to.

"Roy Keane did a good job getting the team promoted and then establishing them in the Premier League.

"He asks for 100 per cent effort and commitment but that is not something I am afraid off. I am looking forward to getting started."