Michael Brown, who became the Liberal Democrats' largest donor when his business gave them £2.4m, was on the run from police last night just weeks before standing trial for alleged fraud and money laundering.

Michael Brown, who became the Liberal Democrats' largest donor when his business gave them £2.4m, was on the run from police last night just weeks before standing trial for alleged fraud and money laundering.

The 42-year-old Glasgow businessman, who made his £10m-plus fortune through shares and property deals, was due to stand trial at Crown Court in London in September.

However, last night a judge at Southwark Crown Court issued an arrest warrant after Mr Brown breached his bail conditions.

A City of London Police spokeswoman said: "A judge at Southwark Crown Court issued an arrest warrant today for Michael Brown. He is due to stand trial on September 8 charged with 18 offences and has failed to comply with his bail conditions. He is charged with money laundering, theft, perverting the course of justice and other fraud-related offences. A further hearing on the case has been listed for August 11."

Mr Brown, who was facing up to 17 years in jail if found guilty, was thrust to the centre of political controversy when he bankrolled the Lib Dems' last general election campaign despite not being registered to vote.

The Glasgow-born businessman, who lives in Hampstead, London, formally denied all the charges during a hearing in June. The theft charges are believed to relate to the tax exile's trading company 5th Avenue Partners. Other counts are linked to claims that criminal assets were transferred via Spanish bank and HSBC accounts.

Last December, Mr Brown was forced into bankruptcy by his own lawyers over an outstanding £20,000 legal bill. The bank successfully froze £20m of the Scot's assets worldwide.

He was the subject of an Electoral Commission investigation after it emerged he was not registered to vote in the UK, despite his massive political donations.

The watchdog found that the party could accept the cash from his UK-based company 5th Avenue Partners. Mr Brown said he gave the money as he believed in then leader Charles Kennedy's ability as a future prime minister.

The commission has put on hold its final decision in the case pending the outcome of the court case. The LibDems have maintained they checked out Mr Brown's background at the time of accepting his donations.

The central claim against 5th Avenue Partners was that its office in London was not trading at the time of the donation, making it an impermissible donor. Mr Brown could not donate personally because he was resident in Spain, and thus fell foul of the ban on foreign donations.

If the commission were ultimately to find against the Liberal Democrats, then the party might have to repay the £2.4m.