Newcastle United insist the club itself is not the subject of an investigation into corruption in football following police raids yesterday.

The City of London Police launched raids on Newcastle, Portsmouth and Rangers and executed search warrants.

The investigation is separate to the inquiry carried out by Lord Stevens and his firm Quest into alleged illegal payments in Premier League football.

The homes of two unnamed individuals were also raided by police officers.

The three clubs all stated they had fully co-operated with the police.

Newcastle plc issued a statement which read: "Newcastle United can confirm that it was visited by the City of London Police.

"The club itself is not the subject of the investigation.

"If the investigation by the City of London Police, or the ongoing internal review of operations by the club's new owners, show that the club has been the victim of any criminal activity, the club will take appropriate action."

Gary Double, director of communications at Portsmouth, confirmed his club was involved in the investigation.

He said: "We have co-operated fully with their search and will not be commenting further."

Rangers confirmed they too had been approached by police.

A club spokesman said: "Rangers Football Club was asked to co-operate with the police investigation and have done so, extending every co-operation.

"We have been requested by police not to comment further while the investigation continues."

A City of London Police spokeswoman stressed the raids were not related to the Lord Stevens inquiry.

She said: "We can confirm that search warrants were served at three football clubs and the homes of two individuals in connection with corruption in football and its impact on owners and shareholders.

"This investigation is a totally independent inquiry.

"It has not been influenced or informed by the Quest inquiry in any way."

Detectives from the economic crime unit at City of London Police are carrying out the investigation into allegations of corruption in football. Last month, they arrested a 61-year-old man in Manchester on suspicion of money laundering.