The newspaper claims it has further evidence of abuse and on Saturday its front page carried a photograph which apparently shows a soldier photographing a bound captive in the back of an armoured personnel carrier.
The picture was allegedly provided by another soldier from the Queen's Lancashire Regiment, already embroiled in controversy over earlier revelations in the Daily Mirror.
The paper says it is "damning proof" that soldiers took "trophy photos" of Iraqi prisoners being abused.
The soldier, named by the paper only as 'Soldier D', told the paper: "There are no rules out there. I saw the man dragged into the vehicle beaten up, kicked and punched. It lasted about a minute. I took the picture as I opened the doors of the vehicle and could see dirt on his shirt and blood on his teeth."
And he claimed soldiers took photos and video footage to look tough and prove to friends what had happened.
He told the Daily Mirror: "You'd come back from Iraq and people wouldn't know what you've been through. If you had pictures you could show them. While we were out there we were told to get rid of all of them. But if they had done a proper search they would have found CDs and all sorts of things.
"There was one CD going round our room with about 500 shots on it. Some were before and after pictures of beatings."
"There was one CD going round our room with about 500 shots on it. Some were before and after pictures of beatings"
Daily Mirror editor Piers Morgan, speaking on Friday, insisted the photographs were all genuine, and represented the tip of the iceberg of abuse in Iraq, which he said was carried out by a small number of soldiers in Basra.
"I believe we've hit the tip of the icerberg here and there were a network, a small number of people who were committing, frankly, atrocities against POWs and detainees in Basra."
The fresh allegations came as US Defence Secretary Donald Rumsfeld offered his "deepest apology" to the victims of abuse in Abu Ghraib prison near Baghdad.