As gas prices rise across the country and stations are increasingly targeted by thieves, a study conducted by an Ontario police force suggests most people who fill up their tank without paying get away with it.

A study conducted by the Hamilton Police found that as many as 60 per cent of people who "gas-and-dash" escape without getting caught.

In some larger cities like Toronto, the rate is as high as 83 per cent.

"We have found that a high majority of cases are not solved," Hamilton police Sgt. Treena Ley told CTV Toronto on Thursday.

Numbers collected by Hamilton Police suggest that nearly 60 per cent of reported cases in Ontario go unsolved.

Of the 1,618 thefts in Toronto last year, 1,335 cases went unsolved.

Of the 368 cases reported in the Peel Region, west of Toronto, 79 per cent went unsolved. In Hamilton, 57 per cent of the 271 reported cases went unsolved.

Hamilton police took a deeper interest in gas station thefts after several recent thefts became violent.

"We have had gas station attendants being spit on, being pushed, nearly being hit by cars. One woman says she had her teeth knocked out," Ley said.

Last month, a 62-year-old gas station attendant was killed in Mississauga, Ont., when he was run over by a person stealing $75 worth of gas.

The thief got away and no arrests have been made. Police say injuries commonly occur when attendants try to stop a theft in progress.

Investigators say that most gas-and-dashes occur in the morning when stations are very busy and lots of cars are at the pumps. Attendants are often too busy to stop the thieves, if they notice in the first place.

A 19-year-old Hamilton woman allegedly robbed the same gas station four times in six weeks before she was arrested.

With a report from CTV Toronto's John Musselman