Photograph developers were thought to have called police after they became concerned about a number of pictures on a roll of film that had been handed in to their shop for processing.

One of the images showed an Iraqi PoW gagged and bound, hanging in netting from a fork-lift truck driven by a British soldier, according to the Sun newspaper.

"Others allegedly depict soldiers committing sex acts near captured Iraqis," the best-selling tabloid said.

The Ministry of Defence confirmed that a soldier was being held in military custody while the Special Investigations Branch of the Royal Military Police launched an inquiry.

If the allegations are found to be true, the soldiers involved would be guilty of a breach of the Geneva Convention which rules that PoWs have to be treated humanely.

"We confirm an investigation is under way into allegations of photos depicting maltreatment of Iraqi PoWs," a ministry spokeswoman said.

"We cannot comment further. But if there is any truth in these allegations the MoD is appalled. We take responsibility to PoWs extremely seriously."

The Ministry of Defence refused to confirm the soldiers's identity, unit or hometown.

But The Sun said the soldier -- which it did not name -- was serving in the 1st battalion Royal Regiment of Fusiliers in southern Iraq at the time of the alleged events.

It said he was arrested by civilian police at his home in the English Midlands, where he was on leave following the US-led war to overthrow Saddam Hussein's regime.

Britain contributed 45,000 military personnel, a naval task force and more than 100 aircraft to the war, and British forces currently occupy the southern part of Iraq.

An investigation is already underway into allegations that a colonel in the Royal Irish Regiment, Tim Collins, abused Iraqi PoWs and civilians. The charges were made by a US army reservist tongue-lashed by Collins for handing out lollipops to Iraqi children.

The 1st battalion Royal Regiment of Fusiliers -- part of the 7th Armoured Brigade, nicknamed the Desert Rats -- is based in Celle, Germany.

WAR.WIRE