HUBBARD — The Warren Fabricating plant in Hubbard was raided by the IRS, with the assistance of the FBI, around 7:30 a.m. Wednesday, and investigators remained at the site until after 3 p.m., according to Craig Casserly of the IRS Criminal Investigation division.

Casserly didn’t disclose any information outside of saying the two agencies were at the Warren Fabricating Plant headquarters, 7845 Chestnut-Ridge Road, on official business.

“The reasoning is sealed in documents in federal court,” Casserly said.

During the search, the plant was closed and workers were sent home.

Casserly said company officials will be able to reopen the plant once the agencies complete their search.

Earlier this year, Paul F. Theisler Jr., 67, of Canfield, pleaded guilty to a charge of aggravated theft, admitting he took between $750,000 to $1.5 million over a period of 12 years. He worked for the company for 38 years and was the Chief Financial Officer.

According to a plea agreement, Theisler was ordered to repay up to $400,000 to the company from his retirement account.

By pleading guilty to a second-degree charge of aggravated theft, Theisler reduced the amount of time he faced in prison from three to 11 years to two to eight years. He was sentenced to two years in August.

“Warren Fabricating has done absolutely nothing inappropriate,” said attorney Ian Friedman of Cleveland. “We are cooperating with all investigating authorities. We don’t yet know any details of any allegations of wrongdoing, and we don’t know the source of those allegations.”

Friedman said the company will be open for business today.

“The 160 employees will be back to work, and they will be doing business the right way — just as Warren Fabricating has done business for 50 years,” he said.

“We look forward to this investigation bringing out the truth — because we know the truth is that Warren Fabricating has held itself to the highest business standards and ethics. That’s how this company established its excellent reputation over the last 50 years, and it’s how Warren Fabricating will continue doing business for years to come.”

According to Tribune Chronicle news partner WKBN 27, agents also searched a home owned by Regina Rebhan Mitchell — a former company executive.