Two Britons arrested in Dubai and wrongly accused of involvement in the 7 July bombings claim they were abused, threatened and deprived of sleep.
Labour MP Shahid Malik has called on the government to investigate
Rafiq Siddique and Alam Ghafoor, from West Yorkshire, were freed after 10 days along with a third UK man.
Dewsbury Labour MP Shahid Malik urged the government to investigate. The Foreign Office said it would ask Dubai for an investigation if the men wished.
No-one representing Dubai authorities was available to comment to BBC News.
A Foreign Office spokesman said the men had been held from 21 July to 30 July, when they were released without charge.
"Our staff gained full consular access to ensure all of their immediate welfare needs were addressed," he said, adding that they had received no reports at the time of the men being poorly treated.
The two men, from Dewsbury and Huddersfield, have now described having guns pointed at their heads, being deprived of sleep and threatened.
Mr Ghafoor said: "We were sat in a restaurant enjoying a meal. A group of men came in, marched us out of the restaurant, threw us into cars, handcuffed and blindfolded us and led us to a building where they started to interrogate us.
"They proceeded to torture us with sleep deprivation and threats of being killed. There was some physical abuse but it was mainly mental.
"There were a lot of veiled threats: 'We can make you disappear. Your family will never know where you are. Nobody will ever know. We can kill you, feed you to the dogs - nobody will be any the wiser.'
"As soon as they hauled us in, the accusation was: 'You are involved in the London bombing. You are either the planners or the financiers or you are involved in the actual making of the bombs.'"
Mr Siddique said: "I am a diabetic, and wasn't allowed any medicine for four days."
Mr Malik told BBC Radio 4's Today programme: "These men - their account, and I certainly believe it - had some very inhumane treatment and there was a complete disregard for a presumption of innocence.
"The Dubai authorities really need to give a full explanation - there needs to be an investigation, a full explanation, at the very least an apology.
"It's a thoroughly frightening experience. It's humiliating. It's degrading. It shouldn't happen to anyone, especially not innocent British businessmen."
The Foreign Office spokesman said: "We take any allegations of human rights abuses seriously.
"If the individuals want to do so, we will raise those allegations with the relevant authorities and ask for an investigation."