Footage of abuse has already been shown to the inquiry
Fears that a lack of army interrogators could lead to the abuse of prisoners were raised a year before the Iraq invasion, a public inquiry has heard.
The former Queen's Lancashire Regiment had no soldiers qualified in "tactical questioning" when Iraqi Baha Mousa was beaten to death, the inquiry heard.
Mr Mousa, 26, died in British military custody in 2003 with 93 injuries.
An inquiry into his death and the treatment of nine other Iraqis held with him opened in London on Monday.
A Ministry of Defence memo in the run-up to the March 2003 war revealed the Army was failing to train staff in prisoner handling and tactical questioning.
Dated March 2002, it said: "The lack of prisoner handling and tactical questioning-trained personnel within deployed force elements risks the loss of potentially accurate, timely and life-saving information/intelligence during our fighting operations...
"The less well-trained our troops are, the greater the chance that they may mishandle prisoners."
The inquiry, led by Sir William Gage, aims to scrutinise the Army's use of conditioning techniques to "soften up" prisoners before questioning.
It will focus on the extent to which tactics like hooding, sleep deprivation and stress positions were known to be unlawful.
Sir William retired from the Court of Appeal last November
The techniques were banned under the Geneva Convention but soldiers said they were common practice within some military units in Basra in 2003.
Gerard Elias QC, counsel to the inquiry, said it was a feature of the treatment of Mr Mousa and the other Iraqi civilians that there were no qualified tactical questioners.
He said: "Those attending the courses for prisoner handling and tactical questioning were largely from the Navy and the Marines."
The inquiry has already heard how Mr Mousa and his fellow detainees suffered humiliating abuse.
They were made to scream in an "orchestrated choir" and one was forced to dance like Michael Jackson, it heard.
The inquiry was shown a film in which Corporal Donald Payne, 36, screamed obscenities at the hooded Iraqi prisoners, calling them "apes".
At a court martial in Wiltshire in September 2006, Cpl Payne was jailed for a year and dismissed from the Army after admitting inhumanely treating civilians.
He became the UK's first convicted war criminal under the International Criminal Court Act. In April 2007, six other soldiers were cleared of all charges.
In July last year the MoD agreed to pay £2.83m in compensation to the families of Mr Mousa and the other men detained with him.
On Tuesday, the inquiry heard evidence that suggests some senior former ministers could be called to explain how banned interrogation techniques came to be authorised.
Attorney General Baroness Scotland has ruled that any soldiers giving evidence to the inquiry will be immune from legal action if it suggests they have lied or withheld information previously.
Their own testimony also cannot be used to decide whether to prosecute them but evidence from other witnesses could still lead to criminal proceedings.
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