RCMP officials confirmed Tuesday night that they are probing allegations that an officer had an “unprofessional relationship” with a witness in an ongoing investigation.

The investigation has links to the 2007 Surrey Six slayings -- B.C.'s worst gang murders in history. The witness was identified following the arrests in April 2009 of the Surrey Six suspects, police said.

The officer, who is an investigator with the Integrated Homicide Investigation Team, has been reassigned to administrative duties pending the outcome of the investigation.

“To date there is no information that any criminal investigation has been compromised as a result of this issue,” RCMP Sgt. Peter Thiessen said in the statement.

Criminal Justice Branch spokesman Neil MacKenzie said in a statement that no evidence provided by the witness had yet been forwarded to Crown Counsel.

“As such it has played no part in any charge assessment or other Crown decisions in any ongoing case,” he said.

CTV News had earlier identified the witness as an ex-girlfriend of Surrey Six suspect Dennis Karbovanec.

Thiessen said that information was not correct.

Six men, including two innocent bystanders, were gunned down in a high-rise apartment in 2007.

Six people were subsequently charged in connection with the killings.

Karbovanec pleaded guilty to three counts of second-degree murder and was sentenced to life in prison.

Five others are awaiting trial.

Eileen Mohan, whose 22-year-old son, Chris, was one of the two innocent bystanders killed, told CTV News Tuesday night that she had been briefed on the internal investigation.

“It’s like we’re seeing a movie here. It only happens in the movies, not in real life. That’s what I thought,” she said.

Mohan said she was initially concerned about how the allegations would impact her son’s case.

But “I was told the case is still very strong,” she said. “This is just one of the hurdles that has come up.”