Daniel Leonard, 32, of Olympia, Wash., is charged with stalking and making harrassing, annoying or obscene phone calls. ((Police photo))

At least 17 Canadians were the victims of an alleged telephone stalker who is now based in the U.S. but was originally from Canada, say police in California.

The Canadian victims include four in Alberta, six in the Toronto area and seven in B.C. One victim alone received 35 harassing calls, Det. Aaron Delgado of the Monterey police told CBC News on Tuesday.

Police arrested Daniel Christopher Leonard, 32, of Olympia, Wash., on Monday. Leonard, a hotel human resources manager, is originally from Manitoba but had been living in California and Washington.

Police alleged Leonard used a "spoofing" service, which caused a fraudulent telephone number to appear on the victim's caller ID and a voice-altering device to mask his identity. The "spoofing" service made the calls almost impossible to trace.

Over the four-month investigation, police said, the caller used the same modus operandi on multiple victims in other parts of California and across North America, including Canada and the states of Washington, Florida and Maryland.

Leonard is now in custody in Washington and fighting extradition to California, Delgado said. He faces numerous charges, including stalking and making harrassing, annoying or obscene phone calls.

In some cases, victims were so traumatized they quit their jobs, stopped answering their phones and were fearful they would ultimately be assaulted.

It is not clear whether Leonard will face charges in Canada, Delgado said.

"That depends on the prosecutor and district attorney and whether victims in Canada made police reports," he said. "A lot of time, people were just ignoring the calls and hanging up."

"If there are victims out there where these kind of phone calls ring a bell, they should be in touch with law enforcement."

Delgado can be reached at 1-831-646-3839.