LYNNFIELD – A Boston mob trial is unveiling the sordid details of an alleged loansharking ring prosecutors say was run by a Lynnfield gangster who lent money through a Saugus sports memorabilia shop and punished customers for failing to repay their debts, among them former Bruins star Gerry Cheevers.According to testimony in U.S. District Court, Cheevers, 68, borrowed cash from Arthur Gianelli of Lynnfield, purported head of a crime syndicate, through Phil Castinetti, owner of Sportsworld on Route 1 in Saugus.Sportsworld recently moved from its longtime store to a new retail space in the Shoppes at Saugus.Fred Wyshak Jr., the federal prosecutor, asserted earlier this week that the syndicate loaned large amounts of money and in turn made millions of dollars in profit between 1999 and 2005. Interest rates allegedly exceeded 150 percent. The illicit business was conducted with the necessary nod of approval from Carmen “The Big Cheese” DiNunzio, then described by the FBI as underboss of organized crime in New England, Whyshak said.Gianelli, 51, is the brother-in-law of John Connolly, a former FBI agent and Lynnfield resident found guilty of collaborating with La Cosa Nostra.Cheever’s name brought added attention to the trial of Gianelli and his associate Dennis “Fish” Albertelli.A two-time Stanley Cup champion goaltender inducted into the Boston Bruins Hall of Fame, Cheevers apparently took a loan from Castinetti and neglected to repay it. The delinquency brought alleged mob enforcer Phil Puopolo to the aging athlete’s door to apply pressure, according to Whyshak.Court documents indicate Cheevers filed for bankruptcy protection in 2004, the same year he repaid a $4,500 loan to Castinetti.Gianelli, his wife Mary Anne, Poupolo, and associate Stephen Russo in September 2006 were named in a 520-count federal indictment charging them and nine others with racketeering, money laundering, operating an illegal gambling business, use of wire communication facilities, extortion, loansharking, arson and interstate travel in aid of racketeering. The indictments stemmed from an investigation into an attempt by Gianelli and others to extort the owners of the Big Dog Sports Grille in Lynnfield.