UK forces have no choice but to hand over prisoners to the Iraqi authorities even though they could be sentenced to death, the government says.
Iraq recently brought back the death penalty
As a signatory to the European Convention on Human Rights, Britain does not normally hand over prisoners to states which have the death penalty.
The convention does not apply to UK troops and the only alternative would be releasing them, the government says.
But Danish forces suspended prisoner handovers because of the death penalty.
Danish Defence Minister Soeren Gade told US reporters: "We wish to know for certain that people in our custody won't be handed over to face the death penalty."
The Liberal Democrats have said Britain should follow suit and refuse to hand over anyone who might face execution.
The interim Iraqi government announced it was bringing the death penalty back on Sunday in an effort to regain control of the security situation.
The Ministry of Defence said in a separate statement that its troops mostly patrolled jointly with Iraqi police and when arrests were made, suspects automatically went into Iraqi custody,
"We are apprehending these suspects of a criminal offence in Iraq in support of the Iraqi security forces and Iraqi efforts to secure law and order," an MoD statement on Tuesday said.
"There will be situations in which we have no choice but to hand over detainees into the Iraqi criminal justice system."
But on Monday, Britain's special representative on human rights on Iraq, Ann Clwyd said the British government would lobby the Iraqis to ditch the death penalty - as it did with other states who had capital punishment.