Scotland Yard has been confronted with another accusation of underhand tactics in its investigation of the murder of London teenager Stephen Lawrence.
It has been claimed that officers secretly recorded meetings they held with Duwayne Brooks, who was with Stephen the night he was killed, and Mr Brooks' lawyer.
Our UK Editor, Lucy Manning reports:
The BBC quoted a senior police source as saying authorisation had been given for two meetings between Mr Brooks, his legal representatives and investigating officers to be recorded.
Jane Deighton, solicitor for Mr Brooks, described the latest allegations as "sinister" and called on the Met to come clean about its activities against her client.
Scotland Yard confirmed that it had received a letter from Mr Brooks's solicitor, Jane Deighton, which had had been referred immediately to Deputy Assistant Commissioner Fiona Taylor, the head of its directorate of professional standards (DPS).
"An investigation into the circumstances of what took place has now been started by the DPS," it said in a statement.
"This investigation will seek to establish exactly what was authorised and what happened to any material which may have been gathered, in the context of the legal framework of that time."
The bugged meetings with Mr Brooks and his lawyers were said to have taken place in the offices of solicitors Deighton Guedalla in Islington, north London, in 1999 or 2000.
Ms Deighton, who was present at one of the meetings, said the police had asked for the meeting so they could brief Mr Brooks about the progress in the murder investigation.
Ms Deighton said she could see no reason for police to record covertly the meetings which they had themselves requested.
"There is absolutely no rational reason. That is very worrying for Duwayne Brooks and for ourselves because it is quite sinister," she told BBC Radio 4's PM programme.
"Why covertly record a meeting that you have asked for? Why unless it is part of something much bigger, why unless in fact covert recordings were happening of Duwayne Brooks and ourselves in different situations? That is what we want to know."