09/30/2013 09:47 EDT | Updated 11/30/2013 05:12 EST

Up to 263 youth abused by former police officer, probe finds

As many as 263 youth may have been abused by former Saint John police officer Kenneth Estabrooks, a private investigator announced on Monday.

Of those, 53 people have been contacted and confirmed the abuse, said 

The remaining individuals have not yet been located, he said.

Those who are still alive now range in age from their 40s to 60s, he said.

The late Estabrooks, a former sergeant, was found guilty in September 1999 of indecent assault against four children, in cases dating back to the 1950s. The abuse included fondling and oral sex.

In 1975, Estabrooks had admitted to sexually abusing children, but he wasn't charged or fired. 

Estabrooks died in 2005.

The City of Saint John hired Toronto-based Investigative Solutions Network Inc. in August 2012 for $100,000 to look into at least one other historical complaint against Estabrooks.

In November, the city revealed there were 12 new alleged victims and allocated another $100,000 to probe complaints.