A new report warns of the increasing tactic of kidnaps and estimates that at least $60m has gone to financing terrorist groups in ransom payments since 2008.

The first annual report on the UK’s strategy for counter-terrorism states that numbers kidnapped last year were close to 50, almost double that of 2010. 13 Britons are among more than 150 foreign nationals who have been abducted in the last four years.

Charles Farr, director general of the Office of Security and Counter-Terrorism, said while Britain refuses to pay, other countries and companies do.

The prime minister and Home Secretary Teresa May are to press for an international consensus in refusing demands at the forthcoming G8 conference in Northern Ireland this summer.

Today’s report also highlights the growing threat from Syria where al-Qaeda affiliates are attracting hundreds of foreign fighters from Europe, including a number from the UK.

Mr Farr said “As and when UK residents return here, there is a real risk that they may carry out attacks using the skills that they have developed overseas.”

Channel Project

The report also reveals more than 500 would-be terrorists have received support through what is called the Channel Project, a £3m-a-year government scheme designed to protect people at risk from radicalisation.

From January 2011 to December 2012, there were 1,274 referrals, of which 243 were offered support through the project, including a handful of school children

Mr Farr said they were not just dealing with Islamist extremism – a reasonable percentage involved those who were developing far-right views.

Among the cases covered by the programme was an Asian man convicted of burglary who expressed anti-western views in jail and was known to have viewed extremist videos online.

He was referred to the project and then returned to education and re-established contact with his family.

Mr Farr said: “I really believe Channel is an essential part of our counter-terrorism.”

He went on: “If you look at the cost by comparison if those people had to be put through the criminal justice system or an investigation, it’s a fraction of the amount. This is quite apart from the damage it does to families and communities.”