The small cell concealed in a bombed-out villa is dusty now, has no electricity, and its door and toilet are gone, bound for a US museum. But it once held Iraqi president Saddam Hussein.

There is no graffiti on the cell's white walls, no remnants of the once-feared dictator's presence.

The narrow concrete platform that held his mattress is empty, and only a few pipes and an outline remain of the stainless steel combination toilet-sink that was mounted on one wall.

The toilet and the door are to end up in a military police museum in Missouri in the United States, according to Lieutenant Colonel Jerry Brooks, the command historian for United States Forces - Iraq.

In the dusty courtyard where Saddam was given an hour a day to exercise, plywood boxes of baked-dry dirt are all that remain of the dictator's garden, in which he is said to have planted flowers and vegetables.

According to Brooks, he spent the other 23 hours a day in the cell, unless he was in court, meeting with lawyers or being interrogated.

Saddam's prison was housed inside one of two bombed-out villas on an island in a man-made lake on Baghdad's outskirts, within the Camp Victory military base, which includes a number of palaces and lakes the dictator commissioned.

The outside of Saddam's one-time prison, which was known simply as Building 114, is scarred by shrapnel, and the uppermost portion of its roof has collapsed.

The villa's exterior was intentionally left damaged so as not to arouse suspicions, Brooks told reporters.

"The exterior was left bombed-out, so people wouldn't know what was going on inside," he said. But "inside, we converted it to a maximum-security prison."

The multi-million-dollar modifications took several months and were "done with a great deal of secrecy," he said. The prison was guarded by military police.

"What you wanted to do was ensure that no attempts were made to break Chemical Ali or Saddam Hussein out of jail," he said.

Saddam was not the only prisoner held on the small island -- his cousin Ali Hassan al-Majid, known as "Chemical Ali" for his role in poison gas attacks, including one on the town of Halabja in 1988 that killed 5,000 people, was also jailed there.

"Saddam was held from 2004 until December 30, 2006," after which he was executed, while Majid was also held there before his 2008 execution, Brooks said.

Majid's cell is a mirror image of Saddam's, though its toilet, having hosted a less famous posterior, is still present.

The facility has three cells, but only two were used. It also contains an interrogation room where Saddam was questioned, with four cameras used to film the sessions.

The prison has been closed since 2009 and without electricity since 2010, Brooks said.

There is speculation it may be turned into a museum after it is handed over to the Iraqi government along with the rest of Camp Victory before the December 31 withdrawal deadline for US forces in Iraq. (AFP)