09/06/2012 03:39 EDT | Updated 11/06/2012 05:12 EST

Former lifeguard charged with sex crimes against boys dating back decades

VANCOUVER - A former lifeguard and YMCA coach has been charged with sex crimes against four boys dating back decades.

Vancouver Police arrested a 70-year-old man at his home on Wednesday after an investigation prompted by tips in June.

Investigators with the sex crimes unit allege the victims were sexually assaulted between 1971 and 1982, when the boys were between the ages of 11 and 17.

The accused worked during those years as a lifeguard for the Vancouver Park Board, instructed at the Vancouver Lifeguard School and volunteered as a coach for the YCMA aquatic safety program.

Police believe there are more victims and are urging anyone with information to come forward, while officials with the Park Board say they currently follow comprehensive policies to protect children.

Abraham Kiewiet is charged with five counts each of indecent assault and gross indecency, and he is scheduled to appear in provincial court on Oct. 10.