MISSISSAUGA, Ont. - A probe into a police dog's attack on a Mississauga woman is stalled because Peel police have refused to turn over records an officer kept on the dog.

Ontario's Special Investigations Unit says it has no grounds to charge a Peel regional police officer with a criminal offence after the woman was hurt June 28.

Michelle Rosales, 21, was treated for two lacerations -- one seven centimetres long and the other six centimetres -- after the German shepherd twice bit her arm in Mississauga Valley Park.

Investigators say they learned each dog is assigned to a particular Peel officer for life, and they requested the officer's history reports on Wyatt, the dog involved.

But the SIU says Peel police refused to provide the reports because they were made by the officer being investigated, and therefore are protected from disclosure.

The agency says the reports would help determine if there were similar incidents involving the dog in the past.