Northampton terminated Brett Sharman\'s contract on Friday, but the English Premiership club insist their decision wasn\'t prompted by an investigation into allegations the player posted a racist message on Twitter about double British Olympic gold medallist Mo Farah. Northampton had conducted a probe into the claims about Sharman\'s alleged racist tweet, which was posted ahead of Farah\'s Olympic 5,000 metres final at London 2012 almost two weeks ago. It was deleted shortly after it had been sent, while Sharman made a public apology and closed his Twitter account.Farah, who added the 5,000 metres Olympic title to his 10,000 metres gold, was born in Somalia and came to live in the United Kingdom as a young boy. However, Northampton insist the decision to release South Africa-born Sharman was due to a knee injury that caused him to miss much of last season rather than the tweet controversy. Jim Mallinder, the club\'s rugby director, said: \"It is always a shame when someone\'s contract comes to an end in these circumstances. \"Brett has contributed a lot to the squad in his time at Franklin\'s Gardens, and we wish him all the best for the future.\" Sharman, quoted in the statement released by Saints, added: \"I have enjoyed my time at the Saints. \"It is a great club with good people, and I am sure that there will be major success coming to Franklin\'s Gardens sooner rather than later. \"The players, management and supporters all deserve that, and I wish them every success.\"