Police said Friday they are worried about the safety of a Canadian filmmaker who disappeared a week ago from his guesthouse in northwestern Cambodia.

Immigration police officer Yut Sinin said an investigation has turned up no clues about where Dave Walker of Edmonton may have gone on Feb. 14. He left behind his phone, laptop computer, passport and other belongings. He said Walker, 58, a former journalist who is a partner in a local film production company, has lived in Siem Reap province for two years.

Yut Sinin said Walker occasionally went to neighboring Thailand, but it seemed unlikely this time. The Phnom Penh Post newspaper quoted Sonny Chhoun, his partner in Animist Farm Films, as saying Walker stepped out of his guesthouse room to let it be cleaned.

"I just want to say, I don't think he went anywhere by himself," Sonny Chhoun was quoted as saying. "I think something is wrong. I don't think he would just leave, with his phone on the charger, and go somewhere. This is very unnatural for Dave. I know him very well."

Shawn Crispin, senior Southeast Asia representative for the New York-based Committee to Protect Journalists, said the organization is "deeply concerned" about Walker's disappearance.

"We call on the relevant Cambodian authorities to leave no stone unturned in their investigation," Crispin said.