ROSEVILLE, Mich. (October 2, 2012)--Police investigating a claim that former Teamsters boss Jimmy Hoffa was buried in a suburban Detroit backyard say testing on soil samples revealed no traces of human decomposition.

The test results were announced Tuesday.

Police have taken down the yellow tape roping off the entrance to the Roseville yard.

Soil samples were removed Friday after officials drilled through the floor of a shed north of Detroit.

Roseville police Chief James Berlin said the ground would be excavated if decomposition were found in the samples.

Hoffa last was seen on July 30, 1975, outside a restaurant in Oakland County, more than 30 miles to the west.

The day he disappeared, Hoffa was supposed to meet with a New Jersey Teamsters boss and a Detroit mafia captain.