Report: Mel Gibson Threatened to "Bury" Oksana in Rose Garden

Credit: Michael Caulfield/OG/Getty Images for Chernobyl Children's Project International

Mel Gibson allegedly threatened to bury ex-girlfriend Oksana Grigorieva in the flower bed of his multi-million dollar mansion, according to a disturbing new report on

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Gibson -- who is currently under a domestic violence investigation by police -- was reportedly heard on tape telling Grigorieva, "I will bury you in the rose garden."

In other recordings, Gibson is allegedly overheard admitting that he beat Grigorieva while she was holding their 8-month-old daughter, Lucia. The attack is supposed to have occurred Jan. 6.

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On June 21, Grigorieva, 40, filed a restraining order against Gibson, 54, stating that he punched her in the face and knocked out her teeth. A Gibson source tells Us Weekly: "They got into it, but he absolutely did not injure her."

The actor then turned around and filed his own restraining order against Grigorieva, prohibiting her from speaking about certain aspects of their case.

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They are both due in court July 20 over the restraining order.