A family doctor who entered into ''no win-no-fee'' arrangements with lawyers pocketed money by compiling fake medical reports for use in personal injury claims, it was alleged today.

GP Lawrence Adler, 63, agreed he would only be paid if his expert opinions led to compensation payouts.

But to get his money, Adler signed off fictitious reports at around £350 a time making up or exaggerating injuries said to have been suffered by claimants.

One said he knew nothing about a personal injury claim being made on his behalf.

The 21-year old claimant - a driver who was unhurt in a road crash - claimed for £800 damage to his car but ended up getting an extra £2,400 from insurers for ''injuries''. He refused to bank the cheque.

Adler, who lives in Radlett, was investigated by police and the Insurance Fraud Bureau before being reported to the General Medical Council. He now faces misconduct charges accusing him of being ''misleading and dishonest.''

The Medical Practitioners Tribunal Service in Manchester was told the events spanned a four year period between 2004 and 2008 when Adler was working at Belmont Health Centre in Harrow.

Counsel for GMC, Mr Paul Raudnitz said Adler had entered into Contingency Fee Arrangements with personal injury lawyers in which he agreed not be paid for work if his reports did not result in a damages payout.

But as a result he had a ''financial interest'' in the outcome of claims and lost any independence as an expert witness - and he failed to declare his CFA arrangement to those insurance firms being sued, the hearing was told.

A motorist known as Claimant A had been involved in a road accident on the M25 in October 2006 when another driver went into the back of his car. But although he was never examined or even spoken to by Adler, two medical reports were prepared about him by the GP in August 2008 without his knowledge, it was said.

A 19-year old shop assistant known as Claimant B had been involved in two unrelated road accidents with motorists between 2007 and 2008 but Adler tailored his conclusions on medical reports compiled for the two insurance companies acting for each driver in a bid to maximise payouts from each firm, it was said.

He told Direct Line who were acting for the driver involved in the first accident that Claimant B had been more severely injured in that crash. Yet he told insurers at Zurich the teenager was more seriously injured in the second crash.

Adler admitted writing the medical reports but claims he did so honestly. He examined a patient he believed to be Claimant A and filed a report based on what he was told. As regards Claimant B he said he assumed each insurance company would have seen both reports and denies deceit.

In 2010 Adler was charged by police investigating an alleged plot to obtain fraudulent payouts worth up to £4m and he was accused of involvement in the laundering of £89,000 between between January 2007, and March 2010. He was also accused of fraud by dishonestly making false representations, namely that Medico-Legal reports and invoices were genuine, with intent to gain.

But in December 2011 the case against him and 13 other people including several lawyers and an insurance broker collapsed at Southwark Crown Court due to lack of evidence. At the time a judge described the prosecution as ''scandalous.''

The tribunal continues.