The inquiry into the alleged abuse of Iraqi prisoners by British troops has become "little more than a whitewash," a former investigator has claimed.
Former Royal Navy and police officer Louise Thomas spent six months with the Iraq Historical Allegations Team (IHAT) before resigning due to lack of progress, she told the Guardian.
She said that she had seen around 1,600 videos of interrogation sessions showing prisoners being abused and humiliated, including being subjected to sleep deprivation and beatings between interrogations.
Ms Thomas accused investigators of being ineffective and showing little concern for what they were seeing.
"I saw a really dark side of the British army," she told the newspaper.
"The videos showed really quite terrible abuses. But some of the IHAT investigators just weren't interested."
IHAT is going through 128 complaints from Iraqis alleging that the British armed forces were guilty of the systemic abuse of detainees between March 2003 and December 2008 when they controlled the Basra area of southern Iraq.
In March this year the Royal Military Police element was removed from IHAT after the Court of Appeal found that it lacked "the requisite independence."
Its role was given to the Royal Navy Police under the command of the Provost Marshal (Navy).
An MoD spokesman said: "All of these allegations of abuse are known to the Ministry of Defence and IHAT, which is why the independent IHAT is already investigating them.
"The MoD has co-operated fully, including the provision of all known evidence."
He added: "Any criticisms about IHAT itself are for the organisation to answer."