Officials in charge of botched storefront sting operations hid serious problems with the program when members of Congress started investigating it, according to three powerful lawmakers.

In a Jan. 10 letter to Bureau of Alcohol, Tobacco, Firearms and Explosives Director B. Todd Jones, Reps. Darrell Issa of California and Bob Goodlatte of Virginia, along with Iowa Sen. Chuck Grassley, renewed their prior demands for answers on a scandal first exposed in 2012 by the Milwaukee Journal-Sentinel newspaper.

Issa is chairman of the House Oversight and Government Reform Committee, and Goodlatte is chairman of the House Judiciary Committee. Grassley is the ranking minority member of the Senate Judiciary Committee.

The newspaper said ATF was operating storefronts posing as pawn and smoke shops in Milwaukee and five other cities across the country.

Federal agents purchased guns and drugs from the shops, created markets for stolen goods and weapons, let felons buy arms, recruited mentally disabled people to help find guns and later prosecuted their recruits, and damaged the properties they rented, according to the Journal Sentinel.

But Issa, Goodlatte and Grassley said in their letter to Jones that when ATF agents briefed members of Congress last April, they made it appear the Milwaukee storefront, named "Operation Fearless," was the only one of its kind.

"Much as in Operation Fast and Furious and Operation Fearless, it appears that poor management was the norm in these other storefront operations," the trio said.

In several cities, agents actually created or boosted the market for stolen goods by buying anything brought into their stores, including stolen guns and electric generators, according to the Journal Sentinel.

And in Portland, Ore., agents set up a storefront across from a middle school, according to the investigation.

Despite the long list of problems, ATF didn't begin investigating Operation Fearless until the congressional inquiry began a year later, according to a May 2013 congressional letter.

"Such a pattern has become all too familiar with ATF's response to scandal," Issa, Goodlatte and Grassley wrote at the time.

ATF also promoted Bernard Zapor, special agent in charge of Operation Fearless, in the fall of 2012, and last summer made him special agent in charge of the Phoenix office that participated in the Fast and Furious gunrunning scandal.

Officials who briefed Congress months before the transfer said the office planned disciplinary action against Zapor for his poor management.

The letter is the fourth sent to Jones probing ATF's poor oversight of the storefronts.

"ATF should have already addressed the problems with these other cases detailed in the Journal Sentinel rather than waiting from a letter from Congress," the three said in the Jan. 10 letter.

The trio asked for details about the five cases and ATF's response to problems with the operations, and gave him a Jan. 16 deadline to set up another briefing on the new information.

Read more about the Journal Sentinel's investigation here.