British authorities tonight rejected claims that Iraqi asylum seekers were mistreated before being deported to Iraq.
Fourteen men claimed they were beaten by UK Border Agency (UKBA) staff at a London airport when they were forced on a plane to be returned to Baghdad.
The men were among 42 deportees sent to Iraq earlier this week and the case has prompted an investigation by the UN Refugee Agency.
Andrej Mahecic, a spokesman for the UN High Commissioner for Refugees (UNHCR), said they were "concerned" by the accounts but tonight the UKBA rebutted the claims.
David Wood, strategic director of criminality and detention group of the UKBA, said: "We reject all allegations that Iraqi returnees removed from the UK were mistreated by our staff.
"We can confirm that 42 Iraqi nationals were removed on a chartered flight to Baghdad on Wednesday 16 June.
"We would prefer that those with no basis of stay in the UK left voluntarily.
"However, where they refuse to do so, we will take steps to enforce their departure.
"All detainees had no right to remain in the UK and their appeals were dismissed by the courts."
One of the deportees said he and others were beaten by UKBA personnel to force him off the plane in Baghdad.
The man, Sherwan Abdullah, a Kurd, told the BBC: "They were grabbing us, they told us if you don't come down, we're gonna beat you badly, and we're gonna take you out."
He added: "If somebody wasn't willing to come out, they grabbed them, they grab the neck, they nearly killed them, they nearly kill them, these people cannot breathe."
Mr Mahecic said the UNHCR was looking into the allegations.
He said: "We are concerned and are looking into the accounts that these people are making. Fourteen of the 42 were interviewed by UNHCR lawyers in Baghdad.
"The men claim that they were beaten while being forced on to the plane. We met with six of the men and we saw fresh bruises that indicate mistreatment.
"The remaining 36 are still at Baghdad airport but the lawyers have spoken to another eight of them over the phone, and all those who were interviewed said that the 42 were deported against their will."
Critics said the case yet again highlighted UN concern at Britain's insistence on returning failed asylum seekers to Baghdad despite advice that parts of the city remain unsafe.
Donna Covey, chief executive of the Refugee Council, said: "For a refused asylum seeker, being returned to their country of origin can be an extremely distressing experience, so removals must always be conducted in a dignified and safe manner.
"But, first and foremost, it is alarming that our Government is still sending Iraqi asylum seekers back to Baghdad despite UN advice that it is unsafe to do so.
"The Government is showing a cavalier attitude towards the welfare of these people, in an exercise which is both costly and unsustainable.
"It would be both cheaper and more humane to help those Iraqis who want to go home voluntarily to do so."