Chelsea could be refunded the £16 million transfer fee paid to Manchester United and Lyn Oslo for John Obi Mikel if Morgan Andersen, a former Lyn director, is convicted of forging the Nigeria midfield player’s first professional contract.

It is understood that Svein Holden, a Norwegian public prosecutor bringing the case against Andersen in a fraud trial in Oslo this week, will argue for the settlement to be cancelled on the grounds that Mikel’s contract with Lyn was invalid, making him available as a free agent.

Chelsea are monitoring the trial, but cannot comment publicly because they signed a confidentially agreement when the compensation package was agreed in June 2006, with United and Lyn receiving £12 million and £4 million respectively to facilitate Mikel’s move to Stamford Bridge.

Chelsea are wary of reopening the wounds of a bitter dispute that plunged almost farcical depths three years ago when Mikel disappeared amid allegations of kidnapping, intimidation and fraud. It is now clear that much of the uncertainty sprang from confusion over who owned Mikel, with Chelsea claiming that they had reached an agreement privately to sign a teenager who was playing as an amateur and United announcing his signature days after his 18th birthday in April 2005.

Andersen’s trial is expected to last two weeks and Mikel and his agent, John Shittu, could be called to testify via videophone. Andersen denies all the charges.