Relatives of six Sussex-trained military police killed by a mob in Iraq say they fear the inquiry into their deaths will be a cover-up.

They have criticised the Government's handling of the investigation, claiming it was taking too long and could last up to three years.

The Redcaps were killed as a crowd surrounded a police station at Al Majar Al-Kabir, near Basra, in June this year, seven weeks after the war ended.

Appearing on BBC 1's current affairs programme Real Story, Tony Fisher, whose brother Simon Hamilton-Jewell died in the attack, was asked how confident he was that the Army report would be truthful.

He said: "On a scale of one to ten, 0.5 because we, in three and a half months, have received virtually no information.

"What it will be is a cover-up because they don't like to admit mistakes.

"They let six men go into a town lightly armed, no proper radio communications, and can't even see there is a problem around them and leave them to die.

"The waste of six lives, the complete waste of six lives. Someone has to answer for that."

Sgt Hamilton-Jewel, 41, was shot dead alongside Lance Cpl Thomas Keys, 20, Cpl Russell Aston, 30, Cpl Simon Miller, 21, Lance Cpl Ben Hyde, 23, and Cpl Paul Long, 24.

They were members of the 156 Provost Company, attached to 16 Air Assault Brigade, based in Colchester, Essex, and were trained at the Roussillon Barracks, Chichester.

So far, the Army has failed to find their killers and it is feared the gunmen may have fled Iraq.

Cpl Keys' father, Reg, said: "They let those six lads drive into that town lightly armed, with inadequate communications.

"Incompetence is the word to sum it up. Absolute incompetence.

"There was Thomas and his five brave colleagues standing side by side trying to hold off a frenzied Iraqi mob armed with high velocity weapons, baying for their blood.

"It is horrific to think my 20-year-old son has witnessed this and someone has stood over his body and finished my dear, darling son off.

"You hand him over to the Army hoping they are going to be responsible. But I feel on this day the Army were irresponsible and I can't forgive them."

Mike Aston, father of Corporal Russell Aston, 30, from Swadlincote, Derbyshire, said: "Someone, somewhere in the MoD or the Army got it wrong. If they hadn't our boys would be alive today."

An MoD spokeswoman said: "The RMP fully understand the families' desire for an early conclusion but it is vital to ensure that the investigation is as thorough as possible."

Real Story will be shown on BBC 1 tomorrow at 7.30pm.