CBS News said federal prosecutors told a judge last month that Ingmar Guandique had been convicted of Levy's murder based on the help of a witness whose credibility is now in doubt.
The judge then sealed court records and issued a gag order for safety reasons, CBS News said, and spectators were kicked out of the courtroom in a subsequent hearing in January.
The case is now shrouded in secrecy.
, "Whether they have to have a new trial or have another suspect, or whatever, we don't know," Chandra Levy's father, Robert said. "They can't tell us because it's secret."
Levy disappeared in 2001, CBS News reported, and many suspected her congressman, Gary Condit.
One year later, her remains were found in Rock Creek Park, CBS News said.
Guandique was convicted in 2010, without any physical evidence, although another prisoner said Guandique had confessed to the crime.
CBS News reported two women said Guandique had attacked them in Rock Creek Park after Levy disappeared.