The UK's support for the CIA's global rendition programme after the September 11 terrorist attacks on the US was far more substantial than has previously been recognised, according to a new research project that draws on a vast number of publicly available data and documentation.

Evidence gathered by The Rendition Project – an interactive website that maps thousands of rendition flights – highlight 1,622 flights in and out of the UK by aircraft now known to have been involved in the agency's secret kidnap and detention programme.

While many of those flights may not have been involved in rendition operations, the researchers behind the project have drawn on testimony from detainees, Red Cross reports, courtroom evidence, flight records and invoices to show that at least 144 were entering the UK while suspected of being engaged in rendition operations.

While the CIA used UK airports for refuelling and overnight stopovers, there is no evidence that any landed in the UK with prisoners on board. This may suggest that the UK government denied permission for this. In some cases, it is unclear whether the airline companies would have been aware of the purpose of the flights.

Some 51 different UK airports were used by 84 different aircraft that have been linked by researchers to the rendition programme. Only the US and Canada were visited more frequently. The most used UK airport was Luton, followed by Glasgow Prestwick and Stansted. There were also flights in and out of RAF Northolt and RAF Brize Norton.

The CIA's use of UK airports was first reported by the Guardian in September 2005. Jack Straw, the then foreign secretary, dismissed the evidence, telling MPs in December that year that "unless we all start to believe in conspiracy theories and that the officials are lying, that I am lying, that behind this there is some kind of secret state which is in league with some dark forces in the United States … there simply is no truth in the claims that the United Kingdom has been involved in rendition."

Straw told the same MPs that media reports of UK involvement in the mistreatment of detainees were "in the realms of the fantastic". Documentation subsequently disclosed in the high court in London showed that Straw had consigned British citizens to Guantánamo Bay in Cuba after they were detained in Afghanistan in 2001.

He is also being sued by a Libyan dissident who was kidnapped and allegedly rendered to Tripoli along with his pregnant wife, after secret files seized during the overthrow of Muammar Gaddafi detailed the role that MI6 played in the affair. Scotland Yard is also investigating the UK's role in renditions to Libya.

Shortly after September 11, the US government asked for permission to build a prison on the Indian Ocean atoll of Diego Garcia, a British overseas territory that is one of the Chagos Islands and leased to the US for use as a military base. This plan was shelved after a Royal Marines officer produced a report that highlighted the logistical difficulties, and the prison was instead built at Guantánamo.

However, Diego Garcia was used for a small number of rendition operations – despite repeated claims by the British government that this had not happened – and a number of human rights group remain convinced that prisoners were incarcerated there.