Scotland Yard Thursday said it was investigating reports that calls to its anti-terrorism hotline were taped by someone not connected to the police. The incident reportedly did not involve any terrorist group.
According to the Telegraph, an organisation that called itself "Teampoison" claimed to have carried out the hotline attack in response to the detention of innocent people on terrorism charges.
The group said it launched a "phone-bombing" exercise against the anti-terror hotline, making non-stop phone calls for 24 hours.
The activity led to phone lines being jammed and genuine callers being unable to get through and report potential terror threats.
Hackers then illegally intercepted an internal call between officials reporting the incident and posted the recordings online.
"We are aware of an issue whereby telephone conversations relating to the anti-terrorist hotline have been recorded. Officers are currently looking into the matter and appropriate action will be taken," the Guardian quoted a police statement as saying.
A source told the Guardian the incident was not believed to involve any terrorist group. Another said the incident was not related to any sort of phone hacking.
The department did not comment on the report that the calls had been recorded by hackers.
The Guardian said police could not categorically say there had not been a security breach.
In February, hackers from Anonymous released a recording of a conference call between the FBI and British police in which they were discussing efforts to catch hackers.
Recently, the British Home Office website was also targeted by Anonymous hackers who shut it down for at least an hour.