TORONTO - The Toronto Humane Society will remain closed for weeks as animal welfare investigators pour over hundreds of thousands of files under the authority of a search warrant that the society vowed Monday to challenge.

"We will be pursuing legal options to contest the validity and the scope of the warrant," humane society spokesperson Ian McConachie said after learning that the facility would not reopen Tuesday.

The humane society had argued that the warrant expired at midnight, but a lawyer for the Ontario Society for the Prevention of Cruelty to Animals said a justice of the peace supported their view that there was no time limit.

"As long as we continue to be in possession of the premises, and as long as we are continuing to search, we finish when we finish," said Christopher Avery, who added there was never a "sunset clause" on the warrant.

Last Thursday, the OSPCA raided the humane society and said it found animals in such poor health that seven of them have had to be put down since. Investigators said they found a mummified cat on the premises, which one OSPCA official described as a "house of horrors."

The raid resulted in animal cruelty charges against five employees.

The humane society maintains there are sick and injured animals at the facility because it is a hospital, a place to "return animals to health, not simply euthanize them."

Avery said there are still hundreds of thousands of pages of materials to sift through, even before the organization begins looking at computer files.

"We're trying to do this in a way that's as non-intrusive as possible," Avery said.

"While we have the right to grab the computers off the desk, and every piece of paper out of the building, that would leave the THC unable to operate and that is not our intention."

McConachie claims the operations of the humane society have already been disrupted after the OSPCA cancelled overnight shifts and used its private security firm to intimidate volunteers.

"Animals will potentially be at risk because animals are not being admitted, adoptions are not being done," he said. "These animals deserve the right to find a new home."

OSPCA investigator Kevin Strooband said the timeline for opening the building could be weeks away.

"We're looking at the potential of three weeks and we're going to take it day-by-day," said Strooband.

Humane society president Tim Trow, general manager Gary McCracken, head veterinarian Steve Sheridan, manager Romeo Bernadino and shelter supervisor Andy Bechtel were all charged with counts of conspiracy to commit an indictable offence and cruelty to animals.

Everyone but Sheridan was also charged with obstruction of a peace officer, for allegedly hiding and euthanizing sickly animals prior to a June OSPCA visit.