A piano teacher who gave lessons in private homes has been charged with three counts of sexual assault, the Coquitlam RCMP said Tuesday.

"All those counts are against former students. They are teens and pre-teens," Cpl. Michael McLaughlin told CBC News.

Police are investigating the "substantial" possibility that there are more alleged victims who have yet to come forward, McLaughlin said.

"It's very important that we speak to any students over a period [from] about 1998 to now who believe they may have been victimized."

Dmytro Kubyshkin, who also uses the first name Dmitri, operated under the company name DM Piano School, police said.

McLaughlin confirmed the investigation had been ongoing for some time. "With allegations this serious you've got to be absolutely sure."

Crown counsel approved the three charges on Monday, he said. "We moved quickly. Naturally, it is such a serious file we had to make sure we got the information out there right away."

Kubyshkin, 67, was arrested Tuesday and is in custody, but is expected to be released either late Tuesday or early Wednesday on conditions which aren't yet known, McLaughlin said.

Police say Kubyshkin was not previously known to them. He is described as Caucasian with white hair, blue eyes, medium build and a Russian accent.

Police urge possible victims to call the Coquitlam RCMP non-emergency number at 604-945-1550 and ask for the Investigative Support Team.