OTTAWA - Police were shoring up their investigation with additional resources as a funeral was held Tuesday for a high-profile couple killed in a mysterious triple homicide.

RCMP and Ontario's chief forensic pathologist have been called in to help Ottawa police investigate the deaths of retired chief justice Alban Garon, his wife, Raymonde, and an elderly friend, Marie-Claire Beniskos.

Dr. Michael Pollanen from the Ontario Centre of Forensic Science in Toronto was meeting with local investigators at the scene of the grisly slayings.

The cause of their deaths is being withheld over concern about compromising the investigation, although the three were reportedly bound to chairs and had suffered severe beatings.

A criminal behaviour analyst from the provincial police behavioural sciences section was also aiding with the investigation.

The three victims were discovered in a luxury condominium in Ottawa's east end June 30. It's believed they were killed nearly 24 hours before police were called.

Investigators said there was "suspicious activity" at the condo complex June 27 and 28, and they were meeting with residents of the gated community hoping to gather more information. Officers have also neighbourhood residents looking for any clues that might lead them to a potential suspect.

Police have asked for information from the public, particularly about any suspicious vehicles or people who may have been seen in the area.

A police forensics team was at the crime scene for several days.

Tuesday's service was held at Notre Dame Cathedral Basilica in Ottawa.