Photos of an aspiring model said to be involved in a relationship with an RCMP officer and a convicted murderer have been altered to protect her identity. ((CBC))

The woman with whom an RCMP officer in the Surrey Six murder investigation was allegedly having an affair is pregnant with the officer's child, CBC News has learned.

Sgt. Derek Brassington was reassigned to desk duties at the beginning of December after senior RCMP officers learned of the alleged affair.

The woman is allegedly two months pregnant with Brassington's child, police sources close to the investigation have told CBC News.

On Thursday, the officer was not at his White Rock home, which he shares with his wife, who is also a police officer.

Brassington was one of several investigators of the October 2007 multiple murder in a Surrey highrise, which cost the lives of four people believed to be in the drug trade and two innocent bystanders.

Six men were charged in connection with the killings. One of them, Dennis Karbovanec, has pleaded guilty to second-degree murder.

The unidentified woman alleged to have had the affair with Brassington is an ex-girlfriend of Karbovanec and also had a relationship with Jamie Bacon, another of the men charged in the Surrey Six homicides, the anonymous sources have told CBC News.

Aspiring model

The impropriety of the alleged affair with Brassington is based on the woman's role as a potential witness in the Surrey Six trials, scheduled to begin in 2011.

The woman was said to be an aspiring model who had posed for pictures found on the internet.

Police said they are concerned for the safety of both the woman and Brassington.

"There are some safety concerns," RCMP Sgt. Peter Thiessen told CBC News on Thursday.

Chief Supt. Janis Armstrong said the RCMP were taking the allegation against Brassington seriously and the professional standards unit is conducting an internal investigation.

"I would characterize him as a seasoned investigator, and should the allegations ring true, then yes, he should have known better," Armstrong said.