WASHINGTON – A House panel on Wednesday investigated accusations of assault, online pornography viewing, and other alleged instances of workplace misconduct at the Environmental Protection Agency (EPA).

The Office of  Inspector General (OIG) – the official watchdog tasked with overseeing the agency – is accusing EPA’s Office of Homeland Security (OHS) of impeding its independent investigations into employee misconduct, computer security, and external threats.

The small office of about 10 employees is overseen by EPA Administrator Gina McCarthy’s office.

The dispute between the OIG and OHS came to a climax last year as House Republicans investigated the EPA’s handling of John C. Beale – a former deputy assistant administrator who pleaded guilty in federal court last fall of defrauding the agency out of nearly $1 million between 2000 and 2013 in unearned pay and bonuses. OHS initially investigated Beale, who falsely claimed he was working undercover for the Central Intelligence Agency to explain his absences, before the inspector general’s office was made aware of it several months later.

Patrick Sullivan, assistant inspector general, said OHS has refused to share information, citing national security concerns.

“Under the heavy cloak of ‘national security,’ the Office of Homeland Security has repeatedly rebuffed and refused to cooperate with OIG’s ongoing requests for information or cooperation,” Sullivan testified before the House Government Reform and Oversight Committee. “This block unquestionably has hamstrung the Office of Inspector General’s ability to carry out its statutory mandate to investigate wrongdoing of EPA employees.”

He said OHS has also failed to report allegations of misconduct by agency staff.

“I am very concerned that vital information regarding suspected employee and contractor misconduct is being withheld from the OIG. Because OHS continues to block my office’s access to information essential to the OIG’s work, I cannot assure the committee that we are doing everything possible to root out other ‘John Beales’ who may be at the EPA or other malfeasance of similar magnitude,” Sullivan said.

Sullivan said the OHS has no statutory authority to do law enforcement and investigative work, even though the office “continually has stated that there are intelligence directives and guidelines that provide it authority to withhold information from and avert oversight by OIG.”

House Oversight and Government Reform Committee Chairman Darrell Issa (R-Calif.) said the EPA is “truly a broken agency,” adding that the employee problems have become “intolerable.”

“John Beale’s behavior did not happen in a vacuum,” Issa said. “In fact, it was just the tip of the EPA’s fraudulent iceberg.”

The panel revealed several allegations and cases of misconduct by EPA staff.

In one case, an employee received a full salary and benefits for at least one year even though he is physically unable to do any work.

In another case, an EPA manager allowed an employee with a debilitating disease to stay home and not report for work for several years. For the past five years she allegedly produced no work, though she was paid roughly $600,000.

Another EPA employee hired 17 of her family members and friends as paid interns. She also paid her daughter – who also works for the agency – a cash bonus out of her agency’s budget account.

Allan Williams, EPA’s deputy assistant inspector general for investigations, said an EPA employee downloaded more than 7,000 pornographic files onto a government computer.