Election results in Wales caused the alleged swearing by Mr Blair

Former Downing Street spin doctor Lance Price claimed in his diaries that Tony Blair swore over bad Labour results in the 1999 Welsh assembly election.

He was interviewed by North Wales Police in London on Wednesday as part of their investigation.

A Downing Street spokeswoman said Mr Blair had not been interviewed.

Following the two-hour interview by a chief inspector from North Wales, Mr Price commented: "I thought it was an extraordinary waste of public money."

A North Wales Police spokeswoman said: "Following a complaint North Wales Police are investigating the circumstances of the anti-Welsh comments attributed to the Prime Minister in the serialisation of Lance Price's book."

Mr Price is due before the Commons Public Administration Committee on Thursday as part of its investigation into memoirs published by public servants.

Toned down

In a draft version of his memoirs, which were serialised in the Mail on Sunday prior to publication, Mr Blair is quoted as saying "f*****g Welsh" repeatedly as the election results arrived, and Labour won only 28 of the assembly's 60 seats.

It was toned down in the final published version to read: "TB f-ing and blinding about the whole thing."

Mr Price previously told BBC Wales he did not believe the prime minister had anything against the people of Wales, but instead was talking about the Wales Labour Party.

In October, the Crown Prosecution Service (CPS) said preliminary North Wales Police inquiries showed no grounds for more investigation of the comments.