The Liberal Democrats' biggest donor, who was due to face a multimillion-pound fraud trial within weeks, is on the run.

Michael Brown, 42, who gave the Liberal Democrats £2.4million in 2005, was on bail and expected to face trial in September, charged with 18 offences relating to money laundering, theft, perverting the course of justice and other fraud-related offences.

However, he has failed to report to his local police station on at least three occasions and has not been seen at his flat in Hampstead, North London, for weeks, The Times has learnt.

Police were granted a warrant for his arrest yesterday and it is understood they believe that he could have left the country. The disclosure will anger prosecution lawyers who had opposed Mr Brown's applications for bail. On two previous occasions he has been accused of running away from court proceedings.

Friends of Mr Brown told The Times yesterday that he had not been seen for some time. One alleged: “He has done a runner. Everyone is furious, and a bit concerned for his safety.”

A judge at Southwark Crown Court issued an arrest warrant yesterday, after a request from City of London Police.

The trial had been awaited by political commentators because, if Mr Brown were to be found guilty, the Lib Dems could be asked to repay the donations to the Government. Mr Brown has denied the allegations.

His bail conditions, obtained by The Times, state that he must “reside at a flat in Hampstead, North London”, and report to the local police station “every Monday, Wednesday and Friday”.

Court papers stated that Mr Brown could also stay at the home of Paul and Evelyn Strasburger, who together were the Lib Dems' second-biggest donor before the last general election. The Strasburgers have also bankrolled part of Mr Brown's legal battle.

Mr Strasburger said yesterday it was untrue that Mr Brown was able to stay at his farmhouse. “This is not his address and he has never lived here,” he said, but declined to comment further.

Mr Brown appeared on the political scene early in 2005 after making the donation to the party when it was led by Charles Kennedy.

The Electoral Commission began an investigation into the donation after The Times disclosed that Mr Brown was not registered to vote and his donor company, 5th Avenue, had not traded in Britain. The inquiry by the Electoral Commission has since been suspended.

The Times then reported that he was wanted by the authorities in Florida after allegedly signing cheques that bounced. Mr Brown claimed he was unaware that he was suspected of having fled proceedings.

Jamil Ahmud, Mr Brown's solicitor, said last night that he was also trying to contact his client. “We are in the process of trying to obtain instructions. There have been numerous occasions when Mr Brown has complied with his bail conditions by reporting to Hampstead police station only to find that the police station was closed.”

Ronel Lehmann, Mr Brown's spokesman, said: “We continue to stand by our client, Michael Brown, who we have acted for since 2005. As soon as I receive instructions, I will be in a position to comment.”

The Liberal Democrat's biggest ever donor, who was due to face a multimillion pound fraud trial in weeks, has gone missing.

Michael Brown, who gave the party £2.4m in 2005, was on bail and expected to face trial on September 8.

However, police have returned to court to apply for a warrant for his arrest after he breached his bail conditions.

A friend of Mr Brown, 42, said the development was a “surprise” to those who know him. “We knew nothing about this - he should have been in Hampstead.”

A judge at Southwark Crown Court issued an arrest warrant today for Mr Brown, who was due to stand trial charged with 18 offences. It is understood that he has failed to comply with his bail conditions.

Mr Brown is charged with money laundering, theft, perverting the course of justice and other fraud-related offences. A further hearing on the case has been scheduled for August 11.

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