The jury in the Robert William Pickton trial has been told his younger brother is still under investigation for suspected involvement in the disappearances of women from Vancouver's Downtown Eastside.

Dave Pickton is still being actively investigated, Vancouver police Det. Const. Mike McDonald said while being cross-examined by defence lawyer Richard Brooks at the B.C. Supreme Court in New Westminster on Thursday.

Robert Pickton is being tried on six of 26 charges of first-degree murder in the deaths of missing women from Vancouver's Downtown Eastside, with a second trial to be held later. He has pleaded not guilty to all charges.

Since the beginning of the case, the defence has told jurors to pay close attention to the relationship between the two brothers.

The jury has already heard another police officer describe Dave Pickton as "the brains of the two of them" and heard that he was condescending to his older brother. A third officer said Dave Pickton even told Robert Pickton when to go to bed.

Robert Pickton was arrested in 2002 and the family pig farm in Port Coquitlam, B.C., was subjected to a massive two-year search.

Dave Pickton has never been charged in connection with the missing women.

Defence grills officer on images

In earlier testimony Thursday, Brooks challenged McDonald over two pictures taken of a pig carcass found in a freezer.

Brooks said one photograph of the carcass showed that the frozen pig's leg was broken, but another photograph of the same area showed no damage.

McDonald was responsible for seizing the carcass from the slaughterhouse.

He disputed Brooks' take on the photographs, saying that even though the photos looked alike, they were taken of two separate areas of the leg.

McDonald was also challenged over notes he failed to take during the course of his work on the investigation.

With files from the Canadian Press