James Bulger
James "Whitey" Bulger is alleged to have been involved in 19 murders. FBI

The trial of James Joseph "Whitey" Bulger got underway in Boston on Wednesday, with his attorney claiming that the mobster never acted as an informant for the Federal Bureau of Investigation, as the prosecution claims.

Bulger, 83, is accused of killing 19 people and for running an organized crime network in Boston in the 1970s and 1980s. During these years, the FBI is said to have turned a blind eye to his activities allegedly because he was acting as an FBI informant.

But Bulger’s defense attorney J.W. Carney said in court that he was never in league with the FBI. Carney said that FBI agent John Connolly fabricated details in his FBI informant file to hide his corrupt activities.

“Ask yourself, would an informant be paying tens of thousands of dollars to the agent, or would it be the other way around?" Carney asked, saying that Bulger was paying the FBI agent for information, according to the Boston Globe.

"He wanted to pay for information and received it from corrupt law enforcement officers," Carney said. "The reason Connolly created the file was just a cover-up for why he was being seen with Bulger so often."

Connolly is currently serving a 40-year jail sentence after being convicted of second degree-murder in 2009 for providing Bulger with information that led to the murder of a possible witness, according to US News.

Bulger faces 32 counts of extortion, racketeering, money laundering and firearms possession, and he was indicted in 1995. But Bulger fled before he was charged and eluded law enforcement officers for 16 years before he was arrested in 2011.

Bulger has pleaded not guilty to all charges against him. He was living with his girlfriend in Santa Monica, Calif., and was turned in by a neighbor who received $2 million as reward.