Former Toronto Humane Society president Tim Trow is shown during his arrest on Nov. 26. (CBC)

The Crown has dropped all charges against six former leaders of the Toronto Humane Society, including erstwhile president Tim Trow.

The Crown told a courtroom at Old City Hall on Monday morning that there were several legal problems with a November raid by the Ontario Society for the Prevention of Cruelty to Animals that led to the charges against the five senior members of the society.

Some of the problems include seizures that were too broad and the presence of the media at various times during the execution of the search warrant, the Crown said in a document outlining the reasons it dropped the charges.

"Ultimately, the Crown has concluded that the lawfulness and execution of these warrants were seriously flawed to such an extent that the Crown would be unable to successfully tender the evidence seized during these searches," the prosecutors wrote.

The Crown was also concerned with the OSPCA's use of civilians — including private investigators — during its investigation.

Taken together, these issues ensured there would be no reasonable chance of conviction of any of those charged, the Crown said.

An angry Rob Godfrey, chair of the OSPCA, said at an afternoon news conference that the Crown's decision means "open season for animal cruelty in the province of Ontario."

He added: "We are outraged by the Crown's decision to drop all charges of animal cruelty, conspiracy and obstruction … [against] the former THS staff members."

Godfrey also appealed to Ontario Attorney General Chris Bentley to review the Crown's move.

The OSPCA is a provincial agency charged with enforcing the province's animal cruelty laws and has the power to lay charges both under the Criminal Code and the OSPCA act.

5 charged in initial raid

The OSPCA took over the humane society on Nov. 26, 2009, after a much-publicized raid. Investigators said they found animals that were neglected at the shelter, with some being left to die in cages without proper care and nutrition.

Five senior officials were charged with animal cruelty:

• President Tim Trow.
• General manager Gary McCracken.
• Head veterinarian Dr. Steve Sheridan.
• Supervisor Andy Bechtel.
• Manager Romeo Bernadino.

Charges against Trow, McCracken, Bechtel and Bernadino also included obstruction of a peace officer.

Members of the society's board of directors were charged with five counts of animal cruelty, a provincial offence under the OSPCA Act.

Vijay Kumar, another society leader, was charged in March with animal cruelty. All those charges have now been dropped.

The humane society reopened its River Street shelter on June 28, seven months after it was closed following the raid. A new board and president, Michael Downey, is now in charge, and the shelter's veterinary clinic has been reaccredited by the College of Veterinarians.

With files from The Canadian Press