(adds quote from Blair's spokesman paragraphs 10-11)
By Robin Pomeroy
ROME, Jan 15 (Reuters) - The hanging of two of Saddam Hussein's aides has brought a new wave of condemnation from countries opposed to the death penalty, the accidental decapitation of one of them adding to the sense of revulsion.
Saddam's half-brother, Barzan Ibrahim al-Tikriti, had his head ripped from his body by the noose when he was hanged at dawn alongside another accomplice of the former Iraqi president for crimes against humanity.
"Reports on the gruesome circumstances of today's executions are very disturbing," said Irish Foreign Minister Dermot Ahern.
"I believe it is in the interests of justice and reconciliation in Iraq that the Iraqi authorities now take the step of ending executions."
A few hours after the hangings, European Commission President Jose Manuel Barroso said he backed an Italian-led campaign for the United Nations to agree to a global moratorium on capital punishment.
"I believe in our European values and I take this occasion to thank Italy for all the initiatives that it announced so that, in the framework of the United Nations, we can work together to put an end to the death penalty," he said.
Journalists were shown video of the hanging which appeared to take place on the same gallows at which Saddam was put to death on Dec. 30., an execution that was filmed both officially and unofficially and seen around the world on the Internet.
An illicitly filmed version of the execution showed witnesses made sectarian taunts to Saddam in his final moments.
British Prime Minister Tony Blair, who called the manner of Saddam's hanging "unacceptable", said Britain was opposed to capital punishment but it remained a sovereign choice for Iraq.
"We emphasised that if the executions were to be carried out then they should be done so in a dignified way. Now if, as appears to be the case, that didn't happen, that clearly was wrong," his spokesman said.
The method chosen for the executions should not obscure the seriousness of the crimes that Saddam and his aides committed, the spokesman added.
The Vatican newspaper L'Osservatore Romano lamented that pleas to suspend executions in Iraq had not been heeded: "A cruel manipulation of the justice system has once again made use of the gallows.
"After the execution of Saddam, which in addition was turned into a spectacle in a way that was clearly damaging to personal dignity, there were many calls to move in the direction of dialogue and reconciliation," it said.
"But at the moment it does not look like such a change of tack has occurred."
The new U.N. Secretary-General, Ban Ki-Moon, initially distanced himself from calls for a U.N. ban, saying "the issue of capital punishment is for each and every member state to decide".
He later urged Iraq to act with "restraint" over the death sentences for Saddam's accomplices.
The death penalty is banned in the EU but still exists in 68 nations around the world.