Federal investigators remained tight-lipped Sunday about what was behind the searches carried out last week at Windber, Pa.-based defense contractors Kuchera Defense Systems and Kuchera Industries.

The raids have drawn the attention of many observers in Washington because of the companies' close links to their local congressman, the Democratic chairman of the House Defense Appropriations Subcommittee, Rep. John Murtha.

There is no suggestion that the investigation involves Murtha, and his office said the congressman had not been contacted by any of the agencies involved.

Agents from the U.S. Defense Criminal Investigative Service, which investigates fraud, bribery, corruption and other forms of abuse by Pentagon contractors, executed three search warrants Thursday at western Pennsylvania addresses connected to the companies, spokesman Gary Comerford told United Press International Sunday.

He referred further questions to the office of local U.S. Attorney Mary Beth Buchanan, whose spokeswoman did not return calls or e-mail Sunday.

The Tribune-Democrat of Johnstown, Pa., the first media outlet to report last week's raids, said they targeted the building where both companies are headquartered, and the homes of the two brothers, William and Ron Kuchera, who are, respectively, the chief executive officer and chief financial officer of the two companies.

The newspaper said about 20 agents from the Defense Criminal Investigative Service, the FBI and the IRS took the names and personal details of all 300 or so workers at the companies' headquarters and then sent them home for the day.

Over the weekend, the newspaper, citing multiple but unnamed sources "close to the investigation," added that part of the investigation is looking into the financing of the LBK Game Ranch, a 161-acre hunting range operated as a private business by William Kuchera.

The ranch often is used to entertain Kuchera clients and suppliers, and this past fall, the newspaper said, it "was the site of a high-end fundraiser" for Murtha's campaign, which raised more than $100,000.

Employees and officers of the two companies have made at least $60,000 in donations to Murtha's campaigns and political action committees since 2002, according to Federal Election Commission records.

"Our office has a working relationship with most companies in our district," Murtha spokesman Matthew Mazonkey told UPI. "As far as this case is concerned," he added, "we have not been contacted by any of the agencies involved."

Since 2002 the companies' employees also have donated more than $30,000 to other Pennsylvania politicians, according to The Hill newspaper, including Republicans Sen. Arlen Specter and Rep. Bill Shuster, and Democrats Sen. Bob Casey and Rep. Patrick Murphy.

Kuchera has received millions of dollars in earmarked federal spending at Murtha's behest. Last year, according to Johnstown station WJAC-TV, $8.2 million in earmarks requested by the congressman went to Kuchera.

And according to Capitol Hill newspaper Roll Call, Murtha regularly issues news releases touting the latest contracts Kuchera has received from federal agencies.

In April 2007, for instance, Murtha's office announced the company had been awarded a subcontract from defense giant Raytheon that could be worth as much as $100 million over its 10-year lifetime. The contract was to produce data and guidance equipment for missiles -- called telemetry systems -- that Kuchera said at the time it would have to acquire the capability to build.

"Telemetry manufacturing is a new capability for Kuchera Defense and will require new skill level training for employees," William Kuchera said in the release.