UPDATE: TMZ has learned that Oksana told Sheriff's deputies Mel Gibson threatened her with a handgun at his estate.
PREVIOUSLY: Mel Gibson has reportedly been taped telling his ex, Oksana Grigorieva, that he hopes she will be "raped by a pack of n***ers" and that she deserved his beatings, and now the tapes show he also threatened her life.
A source tells Radaronline.com that Mel told Oksana he would bury her in the rose garden of his Malibu mansion.
"When things in their relationship started going badly and he made the first threats against her, Oksana decided she needed to protect herself," the source said. "She made the recordings and on one of them, Mel is heard telling Oksana, 'I will bury you in the rose garden,' which she believed to be a clear reference to killing her."
The death threat is on the tape turned over to a Los Angeles judge in the custody battle over their baby daughter Lucia, according to Radar.
Mel is currently being investigated for domestic violence.
More:Mel Gibson Oksana Grigorieva Mel Gibson Rant Mel Gibson Mel Gibson Tapes Mel-gibson-domestic-violence
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