An audit by Metro’s inspector general office that found filthy conditions at some of the transit system’s parking garages blamed the agency for its lack of oversight of a contractor whose workers, according to the report, did little to nothing most of the time.

But the contractor, Community Bridge Inc., placed the blame on Metro, saying it had contracted for temporary labor, not a full-services janitorial contract, and had failed to supervise workers properly.

Deborah Washington, the contractor’s chief operating officer, said her firm was hired to supply temporary workers to be managed by the transit agency’s staff. Those workers often reported for work only to find a lack of supervisors, equipment and other materials, such as sanitary gloves for cleaning restrooms, that they needed to do their jobs, she said.

“We had employees that would call us and say, ‘Ms. Washington, the closets are locked. There’s no supervisors here. I haven’t had gloves to clean the restroom,’ ” Washington said in an interview.

The minority-owned firm, whose other clients have included Montgomery County, the Metropolitan Washington Airports Authority and the Department of Veterans Affairs, met with Metro’s management to remedy the problems last year but to no avail, Washington said.

“We knew at that point that we were going to be a scapegoat,” she said, adding that she was “greatly disappointed” by the handling of the contract and the audit. “To take a company like ours and make us at fault like this is greatly disheartening.”

Metro said it has begun phasing out contractors and hiring in-house custodial workers in an effort to improve maintenance at its parking garages, agency spokeswoman Sherri Ly said in a statement. As soon as Metro learned of the inspector general office’s findings, the agency took action to correct the unsafe and unclean conditions, she said.

“All stairwells and landings have been pressure washed, and all garage decks will be pressure washed by the end of April, weather permitting,” she said.

The inspector general’s audit — detailed in a Dec. 31 memo submitted to Metro’s board on Thursday — said the agency spent an estimated $2.2 million over two years for cleaning services that were not carried out. Inspectors documented human feces, bottles of urine, broken glass and overflowing garbage cans at several parking garages over a 20-month period, the audit says.

The report says the unsafe and filthy conditions remained that way for days and sometimes even months at a time. At the same time, OIG investigators observed the workers perform their duties for as little as five minutes during an eight-hour shift before leaving, and found that contract employees were no-shows for three consecutive days at the Vienna station’s north garage. In seven of the nine station garages investigators visited, almost nothing was done while inspectors were checking, the report says.

“The root cause of these issues was the lack of oversight by [Metro] and contractor officials,” the report says. Inspector General Geoffrey Cherrington declined to comment, saying the audit speaks for itself.

Metro’s initial contract with Community Bridge was signed for “temporary labor” in April 2013 at a cost of $1.7 million and renewed afterward, according to Metro’s procurement records. The OIG alerted Metro’s management about the problem in March. With both sides aware that the OIG was investigating, the contract was allowed to lapse in July.

Metro then entered into emergency contracts to ensure its facilities would be cleaned through January 2020. The cost was more than $1 million for August alone — or about half the six months’ estimated cost of the Community Bridge contract, according to a Metro memorandum documenting its response to the audit. The memo says that in the end, the entire tab for emergency custodial services for six months was estimated to cost about $6.4 million — or $4 million more than it would have cost to extend Community Bridge’s contract.