More evidence of alleged cruelty and mismanagement has emerged in the investigation of the Toronto Humane Society (THS).

On Sunday, staff from the Ontario Society for the Prevention of Cruelty to Animals (OSPCA) revealed it had found pet food expired for as long as six years was being fed to seriously ill cats at the shelter.

Investigators also revealed they had to euthanize several cats overnight, including one which was jaundiced and so malnourished it had lost two-thirds of its body weight.

"This is a serious issue that is more evidence the search warrant executed on the THS last Thursday was necessary and the charges laid were necessary," said lead investigator Kevin Strooband.

During last week’s raid, the OSPCA arrested THS president Tim Trow and four other staffers. Those five face criminal offences associated with animal cruelty, while the entire board of directors has been charged with five counts of animal cruelty under the OSPCA Act.

Furthermore, interim president Robert Hambley admitted on Saturday the THS had spent donation money meant for the animals on its legal battles.

"We have a situation at the THS where lawyers came before food for its vulnerable animals," said Judy King, a local animal-care volunteer.

On Friday, an official called the shelter a "house of horrors" after investigators found a cat that had been dead for more than a year, along with animals suffering from severe health problems.