A Delaware County construction-equipment company is under scrutiny in an ongoing federal probe into fraudulent spending at SEPTA, sources with knowledge of the case said Monday.

Federal agents visited the business, MSI Tool Repair & Supply in Upper Darby, on Monday morning on a court order, an FBI spokesperson confirmed. The FBI’s interest in the business was related to misspending at SEPTA, according to sources familiar with the investigation.

SEPTA declined to confirm that MSI was part of a federal probe. The FBI would not say what investigation in particular brought agents to the business Monday.

State business records show that MSI was established in August 2016, but the owner, Mark Irvello, lists himself as running the company since 1990 on his LinkedIn page. It is described simply as a construction company on that page.

» READ MORE: FBI is investigating workers who misused funds at SEPTA

Annette Irvello, named as an employee of the company, wrote of Mark Irvello on LinkedIn: “He is fair and honest. He will tell you if a tool is worth repairing or trash. If you need someone to repair your tools and not get taken over Mark is the man for the job.”

Property records, as well as a source, indicated that Mark and Annette Irvello, who own a home in Broomall, are married. The Irvellos did not return a phone call made to their home. A person who answered the phone at the business Monday morning hung up when the federal agents’ visit was mentioned.

The investigation, initially reported by WHYY’s PlanPhilly, is looking at the conduct of fewer than a dozen SEPTA managers who allegedly misused the transit agency’s procurement credit cards, sources said. The managers were working with at least one outside vendor that cooperated in the fraud, sources have said, and the federal review is looking at MSI in relation to that. The theft could add up to hundreds of thousands of dollars, they have said.

The fraud centered on facilities managers who fabricated fraudulent supply and repair invoices for construction projects. The credit cards used are available to managers for urgently needed, less expensive purchases so they don’t have to wait through a long procurement process. The fraudulent charges were apparently tucked into legitimate purchases, sources said, with the agency being overcharged while managers and the vendor kept the excess money charged to SEPTA, sources said.

SEPTA conducts legitimate business with MSI, transit agency officials said.

“It’s a place where we can, in the course of projects,” said Andrew Busch, a SEPTA spokesperson, “... go there and purchase items as needed.”

Busch would not say if any SEPTA personnel have been fired in the course of the investigation, which has lasted several months and has not resulted in charges. SEPTA has been waiting for the outcome of the FBI probe before taking action, sources said.