D4vd’s family is disputing claims made in an affidavit as part of the investigation into the death of a 15-year-old whose body was found in a car registered to the singer last September in southern California.

Celeste Rivas Hernandez’s remains were discovered after the Tesla belonging to 20-year-old D4vd, whose birth name is David Anthony Burke, was impounded. According to people, police believe the teenager had been dead for weeks. At the time, the singer was nearing the end of the North American leg of his Withered World Tour.

It’s unclear what information law enforcement believes D4vid’s family might have in the investigation, but his parents, Dawud and Colleen Burke, and brother, David Burke, who all live in Texas, are subjects of a court order from that state ordering them to appear before a California grand jury in the case, TMZ reports. The outlet reported in December tha,t per multiple sources, D4vid is considered a suspect and is expected to be charged in Hernandez’s death.

But the Burkes don’t plan to appear in a Cali courtroom without a legal fight.  They claim that the affidavits used to support the Texas court order were so heavily redacted that they leave no clear explanation for why they’re considered material witnesses. They also claim they were never given the chance to challenge the trial court’s determination.

TMZ reports that an appeals court has now given the trial judge 10 days to respond to the family’s concerns.

Earlier this month, Neo Langston, a former Twitch streamer and friend of D4vd, appeared before the grand jury. Robert Morgenroth, president of the singer’s touring company and general manager of his record label, has also been questioned.

LAPD’s Robbery-Homicide Division told People in September that the Tesla had been parked at the location from which it was towed for several weeks, leading authorities to believe Hernandez had been dead for that same period.