The government insisted to the committee it did not support torture
In its latest report looking at UK policy in the war on terror, the parliamentary foreign affairs committee has called for straight answers from the government over any British role in the highly controversial US "extraordinary rendition" policy.
The committee expressed frustration at the lack of clarity from the government about any possible involvement in a process in which the US covertly, and without any legal process, seizes terrorist suspects and flies them for interrogation to third countries - some of which are known to use torture.
One member of the committee described the policy as "effectively torture by proxy".
Questions have been raised recently about whether Britain has any knowledge, or role, in the process.
Stephen Grey is a journalist who has investigated the subject with access to flight schedules.
He claims the two planes linked to the CIA that have been most active in extraordinary renditions - a Gulfstream 5 and a Boeing 737 business jet - have been regular visitors to the UK, although there is no evidence detainees were on board at the time.
"It's effectively an operational base," Mr Grey told the BBC.
"I count at least 40 flights into and out of the country just for the Gulfstream 5."
According to Mr Grey, airports visited by both planes include Glasgow, Prestwick, and Luton among civilian airports, and Mildenhall, Northolt and Brize Norton among military airports.
The 737 was most recently in Glasgow on the morning of 7 February, when it called in on its way to Baghdad, Mr Grey said.
"It's safe to say the UK has been a major staging post for the US-owned jets on their way to or back from carrying out renditions," he said.
"Have prisoners actually been moved through UK airspace? We don't know because, as far as I am aware, the government has never carried out any investigation into this."
The foreign affairs committee found itself frustrated when it tried to mount its investigation into the subject.
The committee wrote a letter to the Foreign Office on 25 February asking a series of detailed questions about UK practices, the possible use of British airspace or territory, as well as whether the government regarded the use of such methods as legally and morally acceptable.
But the government failed to answer the questions "with the transparency and accountability required on so serious an issue", the committee's latest report said.
The chairman of the committee, Labour MP Donald Anderson, told the BBC: "We've posed specific questions and we've not received specific answers."
Sir John Stanley, the senior Conservative on the committee, also said the government had been trying to "deflect" him in answers to parliamentary questions.
The committee also repeated a request for the government to clarify the broader question of whether it receives or acts upon information extracted through torture by other countries.
Critics argue this would encourage the use of torture by those countries.
In a statement, the Foreign Secretary Jack Straw insisted that the government did not condone torture or instigate others to use it and was working to eradicate it.
But he added that if credible information which could stop a terrorist attack was received, it could not be ignored.