House Oversight and Government Reform Committee Chairman Trey Gowdy (R-S.C.) on Wednesday sent a letter to the White House demanding to know how Rob Porter was allowed to work with an interim security clearance, despite being accused of domestic violence.

"The committee is investigating the policies and procedures by which interim security clearances are investigated and adjudicated within the executive branch, and the extent to which any security clearance issued to Porter comported with those policies and process," Gowdy wrote to White House chief of staff John Kelly.

Gowdy asked that Kelly provide information on the security-clearance process and whether it was followed with Porter. He also requested information on when senior officials at the White House were made aware of the accusations against the former staff secretary.

The chairman gave Kelly two weeks to respond.

Gowdy's letter is the first step in the committee's investigation into Porter, which he announced earlier Wednesday, and signals it is serious in nature.

The probe was announced one day after FBI Director Christopher Wray contradicted the White House over its handling of Porter, who has been accused of physically abusing his two-ex wives.

Wray said it gave the White House information about Porter's past as early as March 2017, months before officials said they learned of the allegations. He also said the investigation was closed in January, despite the White House's insistence it was still ongoing at the time of Porter's resignation.

Gowdy sent a similar letter to Wray requesting information about the investigation for Porter's security clearance.

The FBI chief's testimony sparked a new controversy for the White House, which has struggled to move past the Porter incident.

It has raised questions about the credibility of Kelly and other top aides who were responsible for handling his hiring and background-check process.