Silk Road creator Ross Ulbricht is returning to the federal court in hopes of overturning his conviction and life sentence for running what was described as one of the most sophisticated criminal marketplaces on the internet.

Lawyers for the 32-year-old are making an appearance at the Second Circuit U.S. Court of Appeals in New York on Thursday to appeal for a new trial, according to the Wall Street Journal.

For this fresh bid, the lawyers will focus on the U.S. government’s “calculated failure” to disclose the full extent of its federal agents’ misconduct until after the trial ended. The Justice Department revealed more than a year ago that two federal agents, who worked for the Drug Enforcement Administration and Secret Service, had stolen thousands of dollars worth of bitcoin from Silk Road. The agents, Carl Mark Force IV and Shaun Bridges, are serving their sentences in prison after pleading guilty to the charges.

However, U.S. District Judge Katherine Forrest, who presided over Ulbricht’s case, forbade mentioning the two agents to the jury, which Ulbricht’s lawyers believe was “a violation of Ulbricht’s right to a fair trial.”