An "extraordinary number of resources" is being used to find the remains of missing Woodstock girl Victoria Stafford, says the head of Ontario Provincial Police.

OPP Commissioner Julian Fantino told CTV Toronto on Wednesday that the Stafford murder case is "complex" and that investigators are doing what they can to bring closure to the girl's family.

"There are a lot of people dedicated to this -- a lot of people committed to bringing closure to this as quickly as we can," he said in an interview from Fergus, Ont. where police have concentrated their search for the past week.

"We can't bring Tori back but we certainly hope to return her remains to her family and proceed with the court case," he said.

Victoria has been missing since April 8. She was last seen being escorted from her school by a woman.

Last week, police arrested a man and a woman, charging them both with kidnapping. The male suspect has also been charged with first-degree murder.

Despite the arrests and murder charge, police have yet to find any sign of the missing child.

Fantino said investigators have "lots of challenges" to deal with.

"Trying to piece together a comprehensive picture of what has happened is a complex task and that's what we're trying to do," he said.

Fantino said officers are following up on each tip they've received from the public and are "working towards a successful outcome in the judicial system."

The commissioner also expressed his support for the team of investigators that have been working the case.

The police team had come under public scrutiny for hesitating to call Victoria's case an abduction. An Amber Alert -- an urgent bulletin that is issued whenever a child is kidnapped - was never put into place. Authorities have said repeatedly that they did not have enough information about Victoria's disappearance to issue the alert.

On Tuesday, the OPP and the Ontario government announced that a review of the Amber Alert system will be conducted.

Fantino said he fully supports the idea of a review.

"I'm really pleased we're doing that," he told CTV Toronto on Wednesday. "No doubt there will be some good ideas that will come forward."

With a report from CTV Toronto's John Musselman