LYNN – Movie stars Christian Bale and Amy Adams, dressed in ?70s costumes and shielded by black umbrellas, were among dozens of cast and crew who entered the basement of a law firm in downtown Lynn on Friday morning to film an untitled movie.The movie, directed by David O’Russell, is filming in various places around Massachusetts for the next two months, said a spokesperson for White Dog Productions, who declined to give her name.She said the movie is inspired by a real-life 1970s FBI sting operation that eventually led to the conviction of six U.S. Congressmen, among other public officials.But she stressed the movie is a fictional tale.”People think it’s a true story we’re doing, and it’s not,” she said. “It’s inspired by a sting operation, but it’s not Abscam,” she said, referencing the nickname for the infamous sting.The movie is filming in the basement at 31 Exchange St. for much of the afternoon, said the spokesperson.Lynn’s mayor, Judith Flanagan Kennedy, said she believes the film is expected to stay in Lynn until about 5 p.m. Friday.She and aide Mary Fountain toured the film location just before the actors arrived.Parking on Mount Vernon Street is blocked off for various trucks and trailers related to the movie.Kennedy said officials with the movie paid for Department of Public Works overtime to hang signs blocking off parking and hired Lynn Police to detail the scene.The movie is not filming in any public buildings, she said.According to the spokesperson, the movie also stars Bradley Cooper, Jeremy Renner, Louis C.K. and Oscar-winning actress Jennifer Lawrence.Reporters Amber Parcher and Kait Taylor are reporting and will have a full account in Saturday’s edition of The Daily Item