Man pleads guilty in campaign fund case

A former executive with a major Boston real estate development firm has pleaded guilty to underwriting illegal campaign contributions.

Martin Raffol, who was vice president of Winn Residential Co., entered the pleas Tuesday in U.S. District Court in Boston.

Details of the plea agreement weren't immediately released. The maximum sentence on the most serious charge, witness tampering, is 20 years in prison. Raffol faces sentencing Dec. 8.

Federal prosecutors charged the 54-year-old Natick man last month, accusing him of encouraging the firm's vendors to make donations to local, state and federal candidates and then improperly reimbursing them.

In a statement released after he was charged, Raffol's lawyers said he was under intense pressure to raise large amounts of money for politicians and some of the contributions violated campaign laws and regulations.