THE Intelligence Services Commissioner has found that at least 33 people were wrongly spied on by the security services last year.
Amid continued concerns over snooping by the security agencies - MI5, MI6 and GCHQ - more than 10 per of the 318 cases looked at by Sir Mark Waller amounted to wrongful intrusions into privacy.
In total 1,887 warrants to tap phones or look at emails of suspected terrorists were used by the three agencies.
The report comes in the weeke where Tory Home Secretary Theresa May used a speech to make the case for increasing the powers of the security agencies so they can tap into social media.
It also follows revelations that security agencies in the UK may have received information from their counterparts in the USA obtained from companies such as Google.
Sir Mark, a former Appeal Court judge, said that the angencies need to give “separate consideration to the invasion of privacy as part of the test of propoortionality” in using snooping powers.
In his report, Sir Mark stressed that the figures did not show the number of individuals who had been subjected to unacceptable conduct - only that “proper consideration” was given to that risk in those cases.
“The high number of cases in which consolidated guidance is applied demonstrates how seriously it is taken when detainees of third-party countries are concerned,” he said.
He said the cross-check of the paperwork he carried out in a random sample of 65 cases indicated that the guidance was being applied “properly and well”.
Sir Mark said he had been made aware of 33 “reportable errors” in relation to warrants and authorisations issued to the intelligence agencies and the Ministry of Defence during the course of 2013 - three more than the previous year.
“All of the errors reported to me were caused by human error and all resulted in intrusions into privacy to some degree,” he said.
A Home Office spokesperson said: “The Intelligence Services Commissioner has a vital role in overseeing the work of the intelligence agencies. We welcome that his report finds that the powers are being used appropriately and in accordance with the law.
“The Home Secretary said this week that the threats the country faces are changing fast and the UK needs the capabilities to defend its interests and protect its citizens.
“The intelligence agencies need wide-ranging powers to uphold and maintain our safety and security, but they must be used only when necessary and in a way that is proportionate to the threat being faced.”