The search continued Friday for a Woodstock, Ont. woman who hasn't been seen since Tuesday.

Brenda Duncan, 57, called in sick for work that morning but still left home.

Woodstock police say there has been no activity in Duncan's bank or credit card's accounts since her disappearance.

The social worker's work cellphone has not been used either, the authorities told CTV News on Friday.

Police say they have Duncan's passport. They don't believe she has left the country.

Woodstock police have assigned eight investigators to the case. They have been assisted by an OPP helicopter.

They are looking for signs of her whereabouts, including her 2008 red Mazda5 minivan, Ontario licence plate BCSJ 791.

David Duncan, her husband, appealed Thursday night to the public to help find Brenda.

He urged David urged anyone who may have seen a sign of either Brenda or her van to call Woodstock police at 519-537-2323 or Crime Stoppers.

Woodstock police have sent a bulletin to their counterparts across Ontario and to the Canada Border Services Agency.

Duncan describes his wife as a conscientious woman who was dedicated to her family, work and faith.

He reported the disappearance and said this behaviour is very unlike her: "She was the first person to contact you if she was going to be tied up with something from work and late to be home."

David is a pastor at College Avenue United Church in Woodstock.

Coincidentally, young Woodstock murder victim Tori Stafford attended church there. The church was the scene of a memorial for the little girl, found dead in late July 2009.

Duncan said he is praying for his wife's safe return. "We're hoping for an answer to those prayers," he said.

With a report from CTV Southwest Ontario's David Imrie