Calgary police are frustrated after spending more than two hours outside a motel Thursday on a bogus call.

Officers were camped outside the motel on 16 Ave. N.W. after getting a call from a woman who said she was being held against her will by an armed man.

Police say it turned out the call was faked, and there was no victim.

Investigators say its one of at least 50 similar calls targeting sex trade workers in the city in the last 12 months.

Officials tell The Calgary Sun in each case, they’ve typically found a single female, alone and not in distress.

Police are still trying to find a suspect in the case, but believe it may be someone in the sex trade industry trying to get their competitors in trouble.