 Iraqis have demonstrated over the alleged torture of detainees |
The government has denied Amnesty International's claim that detainees held by British forces in Iraq are being denied their basic rights. Amnesty accused British troops of "a gross dereliction of responsibility".
But the Foreign and Commonwealth Office told BBC News the Red Cross and Iraqi Human Rights Ministry had open access to the 43 detainees held by UK forces.
The Ministry of Defence also said international observers were invited into its detention centres.
A Foreign and Commonwealth Office spokesman said the 43 detainees were considered a threat to the Iraqi people and multinational forces, and United Nations Security Council resolutions 1546 and 1637 authorised their detention.
 | We have no interest in interning individuals in Iraq other than to protect Iraqi security personnel and civilians, and British servicemen and women, from attack |
"Stringent review procedures", including "review by senior military officers and a joint review committee with senior Iraq authorities", ensured detainees were freed "as soon as they cease being a threat to security", the spokesman said.
The Ministry of Defence condemned all acts of abuse.
Allegations of wrongdoing were always taken seriously and a police investigation launched when there were any grounds for believing a criminal act might have occurred, it said.
A spokeswoman added: "We have no interest in interning individuals in Iraq other than to protect Iraqi security personnel and civilians, and British servicemen and women, from attack."
The Red Cross were informed when British forces detained anyone - "usually immediately but always within 24 hours", she said.
"The individual's family is also informed," the spokeswoman added.
But Amnesty wants to see much better safeguards to protect detainees.
Former detainees told Amnesty they had been beaten with plastic cables, given electric shocks and made to stand in a flooded room as an electrical current was passed through the water.
UK director Kate Allen said: "Not only are prisoners being held in defiance of international law, but the allegations of torture continue to pour out of Iraq.
"After the horrors of life under Saddam and then the fresh horror of US prisoner abuse at Abu Ghraib, it is shocking to discover that the multinational forces are detaining thousands of people without charge or trial.
"We are very disturbed that people are not being brought before courts and that we are seeing people's human rights being treated in this way," Ms Allen told BBC Radio 4's Today programme.
"There is not an adequate legal framework.
'Fairly random'
"People do not know what the charges are against them.
"They have not come before the courts.
"And they do not know how long they are going to be detained."
People were being detained in a "fairly random" way" and "the injustices taking place are not making anybody safer", Ms Allen added.
'Huge resentment'
"They are not making it safer for Iraqi civilians and they are certainly not making it safer for the British Army.
"This is building up huge resentment.
"It is causing real tension."
Amnesty's 48-page report - Beyond Abu Ghraib: Detention and torture in Iraq - says the multinational forces and Iraqi authorities must take urgent steps to stop human rights abuses if there is to be any hope of halting Iraq's slide towards increasing violence and sectarianism.