The UK Interception of Communications has launched investigation into whether the Britain’s law enforcement and intelligence agencies have been misusing sanctions to access private data, a new report revealed.

According to the Interception of Communications commissioner Anthony May, there had been over half a million incidents in 2013 when several government agencies were sanctioned access to citizens’ phone calls and emails.

The report noted that the number of interception warrants issued in 2013 was 19% less compared to the earlier year, and the number of authorisations for communication data requests also dropped to 514,608 than 570,135 in 2012.

Majority of authorisations were granted to Police and law enforcement agencies, with only 11.5% being granted to the intelligence agencies.

May said that it seems to be a very large number.

"It has the feeling of being too many," he added.

"My office is in the process of undertaking an inquiry into whether there might be an institutional overuse of authorisations to acquire communications data."

May has been involved in studying concerns raised by fugitive US intelligence contractor Edward Snowden associated to the cooperation between the UK’s spying agency GCHQ and the NSA.

In addition, May is also investigating an error in communication service provider (CSP) system, which resulted in false data exposed to majority of public authorities.

"The error in the main caused false negative results to be provided in relation to requests for subscriber information," he said.

"Accordingly no positive harm resulted to individuals. At the time of writing this report our investigation into the cause and impact of this error is still ongoing."

May also concluded that UK’s interception agencies have not performed random mass spying or have slightest interest in examining innocent citizens’ emails, phone or postal communications or their internet use.