MILWAUKEE -

The U.S. inspector general says a flawed undercover sting by federal agents in Milwaukee raises significant management issues for the Bureau of Alcohol, Tobacco, Firearms and Explosives.

A letter sent to congressional leaders by Inspector General Michael Horowitz said the problems uncovered in the Milwaukee sting are of particular concerns given the agency's failures in its Operation Fast and Furious, a bungled federal gun-tracking operation in Arizona.

Horowitz told the congressmen he will decide whether to conduct his own investigation after reviewing the ATF's report on the Milwaukee operation. He said he has been closely following the sting since it was first reported by the Journal Sentinel. The newspaper found agents' guns and nearly $40,000 in merchandise was stolen from the staged storefront in last year's sting.