Brian Cleave, the solicitor of the Inland Revenue, is believed to have called in investigators from the Inland Revenue's special compliance office to find who has been circulating notes criticising the length of his trousers.

Cleave is the head of the Inland Revenue Solicitor's Office, which has around 50 legal staff on four floors at Somerset House.

It is understood that he sent the notes for forensic examination by an outside expert and then called in a team of investigators who went through the waste paper baskets of suspects at his office and took fingerprints.

The two satirical memos are believed to have said Cleave's trousers were too short and pointed out that he took first-class air travel to Brussels while his staff have to travel by second-class rail.

Cleave told The Lawyer: “It's a private matter and it is confidential. I am not going to discuss it with you. There is no criminal investigation. That is all I have to say.”

When asked if there was any investigation at all he repeated: “There is no criminal investigation.”