The mother of DJ AM alleges in a Los Angeles lawsuit against Learjet that her disc jockey son's overdose death was directly linked to a 2008 crash he survived.

The late disc jockey's mother, Andrea Gross, added a wrongful death claim to a $20 million lawsuit filed by her son before his August death, reported Friday.

DJ AM, whose real name was Adam Goldstein, was suing Learjet along with other defendants for the September 2008 jet crash in West Columbia, S.C.

The crash resulted in the deaths of four people, including two crew members, and left Goldstein and rocker Travis Barker injured.

According to Los Angeles court records, Gross amended the lawsuit to include allegations the crash caused her 36-year-old son to turn back to drug use until his Aug. 28 death of a drug overdose.

"The crash ultimately caused Adam Goldstein's death at a later date," the court papers state.

People magazine said Learjet has denied any responsibility for the crash.