A guard present at Saddam Hussein's execution is being questioned over the unofficial mobile phone footage of the hanging, Iraqi officials say.
Saddam Hussein was hanged at the weekend
Iraqi authorities have pledged to track down the person responsible for a video in which the former Iraqi leader was seen being taunted in his last moments.
The US military has said it would have handled the execution differently.
Unconfirmed reports suggest that two of Saddam Hussein's co-defendants may be hanged on Thursday.
Saddam Hussein's half-brother Barzan Al-Tikriti, and a former chief judge, Awad Al-Bandar, were both found guilty and sentenced to death alongside their leader.
An Iraqi government official, Sami Al-Askari, denied the reports that a date had been set for their execution.
Meanwhile, a committee investigating who had made the unofficial film of the execution was questioning a guard at the prison facility where Saddam Hussein was hanged at dawn on Saturday, Iraq's national security adviser said.
Mouwaffaq al-Rubaie was present at the execution.
He said the unofficial video was "disgusting" and that the taunting - including chants praising Shia cleric Moqtada al-Sadr - had damaged relations between Sunni and Shia Muslims.
"Whoever leaked this video meant to harm national reconciliation and drive a wedge between Shi'ites and Sunnis," he told the Reuters news agency.
Haider Majeed, an official in Prime Minister Nouri Maliki's media office, was quoted by AFP as saying: "It's true. One of the guards has been arrested."
The prime minister's office itself has not yet confirmed the arrest, but has acknowledged the statement by Mr Majeed.
Iraq's government has expressed its concern over the release of the video.
The official government video of the execution did not include any audio and did not show Saddam Hussein's actual death.
But in the mobile phone video shot in the gallows chamber men could be heard shouting insults at the prisoner before he dropped through the gallows platform.
Earlier on Wednesday, the US military commander in Iraqi, Maj Gen William Caldwell, said the US would have handled the execution differently, and denied reports that US troops searched people entering the room.
"This was a government of Iraq decision on how that whole process went down," he said.
But White House spokesman Tony Snow said criticism of the way the execution unfolded was deflecting attention from Saddam Hussein's real crimes.
"There seems to be a lot of concern about the last two minutes of Saddam Hussein's life and less about the first 69 [years], in which he murdered hundreds of thousands of people," Mr Snow said.
"That's why he was executed."