A businessman who was held and mistreated in the United Arab Emirates following the London bombings believes he has evidence that British consular officials asked permission from the UK's own security services to visit him while he was detained.

Heavily redacted documents seen by the Guardian appear to indicate that the request to visit Alam Ghafoor was made to an unidentified British intelligence officer and not to officials in the UAE.

Ghafoor is one of several British men who allege there has been British complicity in their detention and torture while abroad. The businessman, who is 38 and from Huddersfield, West Yorkshire, was detained and tortured while on a business trip to Dubai following the London bombings in July 2005.

Ghafoor and his business partner, Mohammed Rafiq Siddique, flew to the UAE on 4 July. They were dragged out of a restaurant as they dined on 21 July. The two British Muslims say they were threatened with torture, deprived of sleep, subjected to stress positions and told they would be killed and fed to dogs.

Ghafoor has obtained copies of correspondence from consular officials to the Foreign Office in London while he was in custody that show those officials were asking someone other than the UAE authorities for permission to see him. Who that person is, and who they represented, is unclear, as their name was censored before the copies were handed over. Some of the reports were so heavily redacted by the time Ghafoor received them that the only words not blanked are his name.

In one email, dated 25 July, 2005, a consular official wrote: "Today I phoned [name withheld] trying to get permission to see them. First [...] told me that there was no need because they would be deported soon. I asked if we could see them today or tomorrow. [...] told me that [...] would check with the UAE authorities... and would let me know. I didn't hear from [...] since then. Tomorrow I'll speak to [...] again."

Ghafoor, who was released without charge on 30 July, is convinced that the individual to which consular officials were turning for permission to see him was a British intelligence officer. At the time of his interrogation, Ghafoor was told that British security services had requested his questioning.

MI5 and MI6 officers who question terrorism suspects they know are being tortured, are acting in line with a secret government interrogation policy, drawn up after the 9/11 attacks. The policy states: "we cannot be party to such ill treatment nor can we be seen to condone it" and that "it is important that you do not engage in any activity yourself that involves inhumane or degrading treatment of prisoners." It also advises intelligence officers that if detainees "are not within our custody or control, the law does not require you to intervene" to prevent torture.

According to Philippe Sands, QC, one of the world's leading experts in international human rights law, the policy almost certainly breaches international human rights.

When Ghafoor asked why he had been picked up, he was shown a photograph and told he resembled one of the 7/7 suicide bombers and must be related to him. His business partner, Siddique, who was also detained and tortured, says he was told he must have been involved in the bombings – not only did he share a name with the bombers – but he lived in Dewsbury, the same Yorkshire town.

Ghafoor said his interrogators questioned his sexuality, as he is not married, and insulted him because he was unable to wash, saying he smelled. He was also punched in the groin.

One interrogator said to him: "In the morning you will be thrown into a pit and the dogs will tear you to bits and I will watch it and enjoy it."

Eventually, he agreed to sign a false confession admitting he was a friend of the bombers and had organised the London attacks. "I wrote a false confession and put crazy things in it like 'I have constant contact with Saddam Hussein and Osama bin Laden'," he said.

He was told he would be shot by a firing squad the following morning.

When Ghafoor returned home, he was diagnosed with post-traumatic stress disorder. His relationship with his partner broke down and he suffered nightmares, anxiety and paranoia.

Ghafoor is furious that there has been no explanation for his treatment, nor an apology. "I would like to know why I was put through this hell and I would like someone to be accountable."

Clive Stafford-Smith, the legal director of Reprieve, a not-for-profit human rights organisation, said: "It is impossible for the victims of torture to move on without truth and reconciliation, yet the British government seems intent on covering up what it has done."

He added: "Until recently, the British security services were told to effectively turn a blind eye to torture."

The Foreign Office said in a statement that Ghafoor and Siddique were not detained at Britain's request. "British consular staff visited them on July 30, 2005 to ensure their welfare needs were being addressed. Their detention was a matter for the Dubai authorities ... they were not detained at the request of the UK government. We do not participate in, solicit, encourage or condone the use of torture or inhuman or degrading treatment for any purpose.

"Wherever allegations of wrongdoing are made, they are taken seriously and investigated as appropriate."