Jeff Lampert, the former chief executive of Heritage plc, had complained that Grant Thornton partner Scott Barnes, who acted as administrative receiver to the company, used an 'untrue sentence' during civil court proceedings in August 2002.

However, the complaint has been rejected. A spokesperson for Grant Thorton said: 'As expected, the investigation committee threw out the complaint made by Mr Lampert saying that there was no case to answer.'

Grant Thornton went on to complain that the institute did not recognise 'vexatious' litigants like the law courts.

'This means that the ICAEW is required to investigate, and in turn members to defend, even the most scurrilous of accusations brought by persistent complainants,' said the spokesperson.

The institute refused to comment.