The bins were put through their paces at the Grizzly Discovery Centre in West Yellowstone, which houses problem bears.

Only one model managed to stand up to the test organised by the state Department of Fish, Wildlife and Parks.

The bears held at the centre have a record of tearing through rubbish containers looking for food.

"These bears are professionals. That's why they're in here," said centre spokesman Randy Gravatt.

Tourists looked on as three types of bins were tested, each containing fish and fish swabbed on the outside.

Two containers were easy pickings, but one showed promise. That container has a special lid and a spring-loaded latch.

Toby, a 850-pound Kodiak, and several other bears tried several times to open the container, but failed.