Royal Military Police were last night questioning a soldier over fresh claims that British troops abused Iraqis.

The soldier, who has not been named, was being interviewed in London after speaking to The Daily Mirror, it was confirmed.

The new claims also concern the Queen's Lancashire Regiment, already at the centre of a torture pictures probe, a Ministry of Defence spokesman said.

"We can confirm that the individual featured in the Daily Mirror is talking to the Royal Military Police this evening," he said.

"We can also confirm there have been no arrests to date."

Soldier "C" has accused colleagues of beating and mistreating Iraqi detainees.

Daily Mirror editor Piers Morgan said he had a dossier of evidence citing at least four separate incidents of "appalling beatings meted out to PoWs".

Mr Morgan told the BBC News: "He will also be naming the names of the people responsible, including corporals and sergeants and some senior officers who he says were culpable in tacitly allowing this to happen.

"He believes there are already ongoing investigations into a number of people involved in this ring of 'bad apples' and that there will be automatic court martials following."

However, the soldier being questioned was not able to confirm that the inflammatory pictures were genuine, the BBC said.

They were published by the Daily Mirror last Saturday along with similar allegations from two other soldiers.

Doubts have been raised about their authenticity and the newspaper has been accused of endangering the lives of British soldiers by printing them.

However, Mr Morgan told BBC News: "I have seen not one shred of new evidence which has caused me to doubt their authenticity.

"I have absolute confidence in the testimony given to us by the two original soldiers who came to us.

"I believe they told the truth about what happened."

The editor said of the photographs: "I am not queasy or worried about them. Everyone expects me to be, but I'm not.

"I'm very confident that what we have exposed here is a massively important issue."

Asked whether he would resign if they were fakes, Mr Morgan said: "People keep saying, When are you going to quit? I say, I'll tell you what, why don't we have that debate if and when anybody produces a shred of evidence that these pictures are not genuine.

"I believe they are genuine images highlighting genuine incidents of abuse."

Earlier, Prime Minister Tony Blair issued his strongest condemnation yet of any abuse.

"Those things are completely and totally unacceptable," he said. "They are inexcusable and there can be no possible justification for them."

"We must do everything that we can do and need to do in order to root out such practices and bring to justice those responsible for them."

Mr Blair added: "We pay tribute to the thousands of soldiers who will be as appalled as we are at any such inhumane treatment, but who are actually doing a job for their country and for the people of Iraq that needs to be done."