AUGUSTA – Carole Swan shook down a plow contractor for $10,000 and sparked a corruption probe by asking for more, a lawyer hired by the town of Chelsea said Thursday.

Swan, chairman of Chelsea’s selectmen, was arrested Thursday on charges of attempting to steal town money. She turned herself in at the sheriff’s office and was taken to jail in handcuffs.

Swan, 52, is charged with aggravated forgery, attempted theft and two counts of improper compensation for services. She posted $25,000 cash bail and was released pending a hearing May 24 in Kennebec County Superior Court.

If a grand jury indicts her on the forgery and theft charges — both felonies — she could be in court sooner, for an arraignment.

The sheriff’s department began investigating Swan, who has been a selectman for almost 19 years, after a contractor told deputies on Jan. 31 that she had asked him to overbill the town so she could receive a kickback, according to a statement from Sheriff Randall Liberty.

Stephen Langsdorf, a lawyer representing the town, detailed three incidents involving the contractor, Frank Monroe of Whitefield, who has had a contract to plow Chelsea’s roads since 2006.

“In February 2010, Carole Swan approached Frank Monroe and put pressure on him to pay her, personally, $3,000 — and he paid her,” Langsdorf said.

“In the fall, the same thing happened, and she convinced him to pay her $7,000 cash,” he said.

Langsdorf said the third request sent Monroe to authorities.

“Last week, Carole approached Frank Monroe and asked him to prepare a bill to the town for approximately 1,700 yards of sand but to only deliver 500 yards. The town would pay him for 1,700 and he was to give her $10,000 of that,” he said.

“He balked, and he ended up cooperating with the sheriff’s department,” Langsdorf said.

“She approves the warrant and pays him for the fraudulent amount and then he’s supposed to give her $10,000. He gave her some money. And she was pulled over and she had the cash in the vehicle,” he said.

Monroe denied any involvement with Swan when contacted Wednesday by the Kennebec Journal. Swan’s attorney, Leonard Sharon, was in court in Bangor on Thursday and unavailable for comment.