TORONTO - The family of billionaire philanthropist couple Barry and Honey Sherman is offering a $10 million reward for information leading to an arrest in the pair's deaths.

A lawyer for the family says a private investigation has uncovered major shortcomings in the Toronto police's probe of the deaths, prompting the couple's loved ones to offer the reward.

The Shermans were found dead in their Toronto mansion last December in what police have classified as a targeted double homicide.

Family lawyer Brian Greenspan says police failed to collect suffient fingerprint and DNA evidence 10 months after the couple's bodies were found in their Toronto mansion.

He says a team he's assembled at the request of the family, including several former homicide investigators and Ontario's former chief pathologist, have uncovered other evidence, including 25 finger and palm prints, that the police had not identified.

Greenspan says the family took the step of hiring private investigators after police erroneously stated they were not looking for suspects in the Shermans' deaths, implying that they died either by suicide or murder-suicide.