The chairmen of a Senate subcommittee on the Homeland Security Committee have canceled a hearing about the alleged misconduct of a key Department of Homeland Security (DHS) official, after that official stepped down from his post this week.

Charles Edwards was deputy inspector general at the Department of Homeland Security, and was the subject of a probe by Sens. Claire McCaskillClaire Conner McCaskillNSA spying program overcomes key Senate hurdle Senate campaign fundraising reports roll in Dems search for winning playbook MORE (D-Mo.) and Ron JohnsonRonald (Ron) Harold JohnsonGOP senators eager for Romney to join them The House needs to help patients from being victimized by antiquated technology Comey’s original Clinton memo released, cites possible violations MORE (R-Wis.). Those two senators lead the Financial & Contracting Oversight subcommittee of the Senate Homeland Security Committee.

The two senators wrote a letter over the summer saying there were allegations that Edwards withheld information in a report about the Secret Service prostitution scandal in Brazil, improperly hired his wife and used federal money to get a post-graduate degree at a Florida school.

To address those allegations, McCaskill and Johnson had planned a subcommittee hearing for Thursday titled, "Alleged Misconduct by the Inspector General of the Department of Homeland Security."

But on Monday, Edwards left his post, and today, he reportedly took a position in the technology department of DHS. McCaskill and Johnson took that as a sign that the inspector general's office was cleaning house.

"Inspectors general are supposed to serve as the eyes and ears of taxpayers within our agencies, guarding against waste, fraud, and abuse of power, and we expect them to abide by the same high standards of behavior they apply to agency officials," they said Tuesday. "We hope that Mr. Edwards' departure will pave the way for a new level of accountability and transparency within the Department of Homeland Security's Office of Inspector General, and we plan to continue rigorous oversight to achieve that goal."

McCaskill and Johnson said their planned hearing for Thursday has been canceled given Edwards's reassignment. They did not say whether a hearing would be rescheduled to address the charges of misconduct.

Cause of Action, which has been investigating Edwards for two years, blasted his decision to step down from his IG post as one that was designed to avoid testifying before Congress.

"Cause of Action sees the failure of the Administration to hold Edwards accountable and Edwards' resignation, less than three days before a Senate hearing, as a cowardly excuse to avoid answering difficult questions about allegations of his abuse and misconduct, some of which may rise to violations of the law, in the Inspector General office," said Executive Director Dan Epstein.

Epstein's group filed a lawsuit that led to the discovery of documents that the group says demonstrates nepotism, mismanagement and some internal complaints about Edwards. Cause of Action has asked President Obama to remove him from his position.