ELKHART COUNTY — With high gas prices, people are trying to protect what's in their tank by using locking gas caps. But they may not work as well as you think.

This past weekend, someone managed to get through locked gas caps on some county-owned cars in Elkhart County. The caps weren't even damaged.

Some people believe the locks were opened using keys from other gas caps. But auto stores say that is impossible because the locks are unique. So, WSBT decided to test them.

Locking gas caps cost about $20.

Elkhart County's Planning Commission bought them for its cars two weeks ago.

This past weekend, someone bypassed the lock and stole 50 gallons of gas out of two trucks with locked gas caps. The department believes someone may have used another key to open the caps.

WSBT bought five locking caps and tested the keys, but only the keys that came with the caps opened them.

"I figure if they want it, they are going to find a way to get it one way or another," said Jeff Maloney, who stopped using his locked cap.

"I don't see any reason to take them off. They are still going to slow some people down," said Bob Watkins, director of Elkhart County's Planning Department.

The department plans to continue using them.

Locksmiths say there is a pressure device that allows people to pop the lock without damaging it.

Police departments say they haven't seen too many locking gas caps popped open yet, but gas siphoning is big problem.