More than 50,000 people were stopped and questioned at Britain's ports and airports as potential terrorists last year under the same counter-terrorism powers used to detain David Miranda, partner of the Guardian journalist Glenn Greenwald, in August.

The Home Office's quarterly terror statistics show that 56,257 people were stopped and examined under schedule 7 of the Terrorism Act 2000, which allows for them to be questioned for up to nine hours without the need for a "reasonable suspicion" that they are involved in terrorism.

The figures show that 2,265 of those stopped at airports in 2012/13 were questioned for more than an hour, and 667 were subsequently detained under other powers.

The number of people arrested in Britain for suspected terrorism offences and subsequently charged with a criminal offence rose by 43 to 105 in 2012/13. Of these, 37 were charged with terrorism-related offences.

In all, 249 people were arrested in connection with counter-terrorism operations in 2012/13, a 21% increase on the previous year. The rise was probably connected with the security operations surrounding the London Olympics last summer, but the Home Office said the number varied each year depending on those held in particular operations.

Of those 249 people arrested, 105 were released with no further action taken against them. Immigration enforcement action was taken against 39, 37 were charged with a terrorism-related offence and 68 were charged under other legislation. So far 23 of the 37 charged with terrorism-related offences have been convicted.

The figures show that 2,297 people have been arrested in Britain on suspicion of terrorism offences since September 2001, when the 9/11 attacks happened in the US. Officials classify 1,941 of the 2,297 arrests as international terrorism, 258 as domestic and 175 as Northern Ireland-related.

At the end of March this year there were 121 convicted prisoners classified as terrorists in British jails, 95 of whom were British. Eighteen of the 121 were classified as "domestic extremist/separatist" prisoners, which includes far-right and animal rights campaigners.

A separate Home Office analysis of the use of counter-terror powers says data on the religious background of those charged and sentenced shows that claims that Muslims have received heavier sentences because of their beliefs are unfounded.