Andrew Getty, J. Paul's Grandson ... Ulcers and Meth Caused Death

Andrew Getty, the grandson of J. Paul Getty, was under the influence of meth ... and his habit was so bad he did an 8 ball a day ... this according to the Coroner's report.

TMZ broke the story, Getty was found dead in March in the bathroom of his L.A. home.

According to the L.A. County Coroner, Getty's ex-girlfriend, Lanessa DeJong, was present when paramedics arrived and appeared to be under the influence of drugs. She told authorities Andrew had a meth problem and did an 8 ball a day.

The official cause of death is a gastrointestinal hemorrhage, but meth was a contributing factor. The autopsy showed toxic levels of the drug.

Getty also had a pharmacy of Rx drugs at his home, including Concerta, Adderall, Norco, as well as Dainabol and Trenabol Acetate (both anabolic steroids).

And according to the Coroner's report, investigators found an interesting clue on Getty's cellphone. There were 2 texts from a person named Robby, who wrote, "Lemme know if you need something. Imma grabbing the good stuff in a minute." The second text reads, "It's a good batch, my man."