FRYEBURG – A 20-year-old New Hampshire woman arrested Sunday is the seventh person to face charges related to a brutal assault on a former Norway man here last month.

Ellen Caughey, 20, of Madison, N.H., was being held without bail Monday afternoon at the Oxford County Jail after waiving extradition. She is charged with three counts of criminal conspiracy.

“She set the victim up, and she drove the victim from Massachusetts to Maine,” said investigator Ian Tait of the Fryeburg Police Department.

Tait said Caughey was arrested Sunday afternoon at her mother’s residence in Bartlett, N.H., by the Bartlett Police Department. Tait said Caughey was the “final arrest” in relation to the March 29 beating of 21-year-old Philip M. Swanson of Hamilton, Mass., and formerly of 187 Main St. in Norway.

“We’ve been in contact with the Federal Bureau of Investigation in regards to possible federal violations that occurred in luring the victim across two state lines,” Tait said. “They are very interested in the case.”

Police have arrested Richard C. Smith, 20, of North Conway, N.H.; Luke R. Clough, 23, of Madison, N.H.; Tyler D. Rogers, 21, of Fryeburg; James R. Keene, 22, of Fryeburg; Richard Flagg, 20, of Conway, N.H.; and Michael Merrill, 23, of Albany, N.H.

The men are accused of beating Swanson with baseball bats, a pistol, and a beer bottle outside Keene’s residence and on a dead-end road on March 29. The attack occurred three days after Smith and Clough had gone to Massachusetts so Smith could purchase marijuana with Swanson’s help. When Smith was robbed of $975 by four armed men, he and Clough thought Swanson had set up the heist, police said.

According to police, Swanson knew Caughey from the Conway area and is Clough’s ex-girlfriend.

Swanson said Caughey showed up in Massachusetts in Clough’s truck the day before the assault and said she’d drive him to her grandmother’s house in Marlboro, Mass., but instead drove to Fryeburg, where the assailants were waiting, police said. He was hauled out of the truck, beaten and then driven to a dead-end road, beaten again, stripped of his clothes, robbed of money and a phone and left in a snowbank, police said.

Swanson managed to get to a home and call for help. He was treated at Bridgton Hospital for severe lacerations, bruises and cold exposure to his feet. From there he was taken to Oxford County Jail on a charge of failure to pay restitution on a prior case, police said.

Though the reports state that Keene’s girlfriend was also under investigation for conspiracy, Tait said Monday that she is not being charged at this time.

Tait said the investigation into the assault included 15 law enforcement agencies in Maine, New Hampshire and Massachusetts. He cited the New Hampshire State Police and police departments in Conway, N.H.; Madison, N.H.; and Malden, Mass., as “crucial” to the investigation.