Tenants who unknowingly rented properties used to launder the profits of an illegal gambling ring are worried about what will happen after the federal government seizes the buildings caught up in a multi-million-dollar bust. Last week, Stephen Mardigan pleaded guilty to running a high-stakes sports betting syndicate and agreed to surrender more than a dozen of his Portland-area properties, including his Baxter Boulevard mansion, to the federal government. But with his sentencing likely months off and June 1 approaching, Mardigan’s tenants are unsure to whom they are supposed to pay their rent, and angry to be affected by their landlord’s years of criminal activity. They worry about ending up the losers in what is believed to be among the largest illegal gambling cases ever brought it Maine. “I’m probably going to be screwed because he wanted to play gangster,” said Rosetta Iannaccone, who runs a sandwich shop in one of the buildings Mardigan agreed to turn over to the feds. Frying cheese steak on the griddle at The 5 Spot, Iannaccone, 31, said she’s concerned that whoever eventually buys the Congress Street building she rents will try to break the lease. She co-owns the Philadelphia-themed restaurant with her husband and said they began renting from Mardigan last April, days before the feds raided his home and started legal proceedings to seize his properties. [Maine man pleads guilty in illegal gambling case, to turn over mansion, other properties to feds] They have a five-year lease, Iannaccone said, “but any new landlord might have grounds to fight that.” As part of his guilty plea to charges of illegal gambling, money laundering and filing a false tax return, Mardigan agreed to forfeit 18 properties he owns in the Portland area.