Dozens of federal employees at an obscure agency that handles appeals of patent applications went years with so little work to do that they collected salaries — and even bonuses — while they surfed the Internet, did laundry, exercised and watched television, an investigation has found.

The employees, paralegals making $60,000 to $80,000 a year, were idle with full knowledge of their immediate bosses and multiple layers of managers and judges who “sat on their hands” waiting for work to give them, a year-long probe by the Commerce Department inspector general’s office uncovered.

The underworked paralegals did little as a backlog of appeals of patent examinations that many of them were hired to help process doubled from about 12,500 in fiscal 2009 to 25,300 last year. Soon after the appeals board brought on additional legal support staff to address a deluge of challenges to decisions by patent examiners, the Patent and Trademark Office imposed a hiring freeze that halted hires of judges needed to handle the appeals.

But they took home more than $4.3 million in pay and about $700,000 in annual performance bonuses of up to $3,500 apiece for “outstanding” work from 2009 through 2013, the report released Tuesday found.

The employees also worked from home. The Patent and Trademark Office set an early example for other federal agencies years ago when it encouraged employees to telework. But the inspector general found that for paralegals in the appeals office, working from home was a green light to abuse the privilege by doing laundry, washing dishes, reading books and a host of other personal activities.

The bonuses included $120,000 for the paralegals’ supervisors, some of whom didn’t even bother to check in with their staff to make sure they had enough work to do.

When it was time to fill out their timesheets, the employees were told by their supervisors to record their hours under a different pay code known as “Other Time,” investigators found.

The practice only stopped last year once patent officials learned that Inspector General Todd Zinser’s office was looking into complaints from three paralegals, all anonymous whistleblowers, about the lack of work.

When it became clear that an investigation was underway, top managers devised other tasks for the paralegals to do, including assigning them to a project writing an article on the history of the appeals board. But the article was never published, the report found. And most of the other work was “busy work” that the inspector general called “feeble, half-hearted and ineffective.”

“I almost don’t blame [the Paralegal Specialists] for watching TV,” one of the chief judges at the appeal board told investigators, “because, I mean, you’re sitting around for 800 hours.”

But the judge and multiple managers did nothing to reassign the paralegals or give them other work, in what Zinser called “a complete breakdown of management.”

“It’s one thing to have idle workers,” Zinser said in an interview, “but in addition to being idle, they received outstanding performance ratings.” He said the Patent Office “displayed a lack of sensitivity” to fee payers who fund the Alexandria-based agency’s $3 billion annual budget.

Patent Office spokesman Todd Elmer said in a statement that the agency is reviewing the report and will issue a response within 60 days. After conducting its own probe and hiring an outside consultant once the inspector general raised concerns, the office has made “structural improvements” to make the paralegal program more efficient, Elmer said. A new management team is in place that is “eliminating underutilization” and revising the way paralegals’ performance is evaluated.

“With new and ongoing improvements, combined with this additional input from the [inspector general], the agency is confident that the [appeals board] will be even more strongly situated to achieve tremendous results for its stakeholders,” Elmer wrote.

The Patent Trial and Appeal board, with about 300 employees in Northern Virginia and home-based telework offices within 50 miles, reviews appeals of decisions made by patent examiners and decides whether challenges made against existing patents are legitimate.

The role of the paralegals, called “paralegal specialists,” is to docket cases, create electronic files, make sure an appeal complies with relevant statutes, and proofread and edit judges’ decisions for grammar and style. On occasion they do legal research for judges.

But they rely on judges to give them work, as opposed to generating it themselves.

Patent appeals got backlogged as the agency had a surge of new examiners between 2005 and 2011, patent office officials said. As the number of patent decisions grew, so did the appeals. But the appeals board did not begin hiring additional judges to adjudicate the new cases until last year, when fiscal pressures eased, officials said.

It is unclear whether the patent office plans to review the generous telework program across the agency, which has been held up as a model for other federal offices.  Zinser criticized the appeal board telework program as lacking in proper supervision and accountability. For example, his investigation found that supervisors barely checked in with the paralegals to see if they needed more work.

“No need to notify me when work is done,” one supervisor told a paralegal in an e-mail Dec. 18, 2012, in response to a message from a paralegal that she had completed her assigned work at 9:25 a.m. that day.

“I think. … It used to get on the supervisors’ nerves, because they knew we didn’t have anything,” the employee told investigators.

Some managers were so fearful of angering the union that represents Patent and Trademark Office employees that they didn’t even consider changing the paralegals’ work assignments or even starting the process of layoffs.

But the report said the appeals board had options it should have explored with the unions. Some managers did not know, for example, whether changing work schedules and assignments even needed to be negotiated.

Managers told investigators that they weren’t surprised that the paralegals were shopping and exercising on government time, even bringing Kindles to the Alexandria headquarters to read when they were required to be there.

One manager said he “wouldn’t have been a bit surprised if there were people who were going out to the golf course.”