The House Ethics Committee is probing Rep. Tom PetriThomas (Tom) Evert PetriBreak the cycle of partisanship with infant, child health care programs Combine healthcare and tax reform to bring out the best in both Overnight Tech: Internet lobby criticizes GOP privacy bill | Apple sees security requests for user data skyrocket | Airbnb beefs up lobbying MORE (R-Wis.) over his advocacy for a defense firm in which he owns more than a quarter of a million dollars in stock. 

The committee will decide how to proceed by Sept. 30, according to Committee Chairman Michael Conaway (R-Texas) and ranking member Linda Sanchez (D-Calif.). 

The independent Office of Congressional Ethics first asked the committee to look into the case in July — a revelation made Monday.

The secretive committee did not reveal the subject of the review, but Petri's office confirmed it is about the stock. 

"I look forward to the Committee on Ethics completing its review," Petri said in a statement. "I remain confident that the Committee will find that I acted properly, and that I reasonably sought, relied on, and followed the Committee’s advice and that I complied with House rules."

In February, Petri himself asked the Ethics Committee to review his advocacy for the defense contractor, Oshkosh Corp., which is based in his district. 

Gannett/USA Today reported in February that the contractor’s stock had gained about 30 percent during his advocacy, which included letters in support of the company and a key contract.

In the February letter, he said he was distressed by the "innuendo" in the reporting and said his advocacy and investment in the company has taken place openly and that he has consulted with the committee about it "from time to time."

Since then, Petri has decided against running for reelection and will step down at the end of the year, which could cut the review short. 

The Gannett/USA Today article in February reported that the congressman owns between $265,000 and $650,000 worth of stock in the defense contracting company, in which he has advocated for in his official capacity on numerous occasions. 

The report highlights the congressman's support on behalf of a $3 billion contract won in 2009 to produce armored trucks and trailers. The congressman spearheaded numerous letters in an attempt to protect and defend the contract. 

At the time, other lawmakers complained to the Government Accountability Office that the company's bid was "unrealistically low.” At another point, the congressman urged the House Armed Service Committee not to redirect funds for the contract.