Middle Age Hollywood

Domestic violence accusations between Mel Gibson and baby-mama Oksana Grigorieva have reached fever pitch: A murder-suicide plot.

The "Passion of the Christ" mega-star allegedly pulled a gun on Grigorieva during a nasty confrontation Jan. 6, according to a new report by Radaronline.com.

He also supposedly choked and punched the Russian beauty twice in the head, all while she was clutching their baby girl, Lucia.

Los Angeles County Sheriff's Department and the California Department of Children and Family Services are both investigating.

Sources told the gossip Web site that the nearly-deadly throw-down went something like this:

Grigorieva went to a basketball game for her son Alexander, 12, leaving baby Lucia home with a nanny. Grigorieva then returned home that evening to a furious Gibson, 54, who stalked through the Malibu house slamming doors and cursing her out.

The fight escalated as "Mel punched her in the mouth and then again in the side of the head," a source with knowledge of the investigation told RadarOnline.com.

The force of the alleged blows threw Grigorieva back onto the bed, and the Oscar-winner supposedly choked her and held a hand over her mouth.

Once she freed herself, Gibson then allegedly pulled a gun from his pocket, pointed it at Grigorieva's head and threatened to shoot her, the children and himself.

"Oksana has told authorities it was horrific and she thought she was going to die," the source said.

Meanwhile, Grigorieva's son allegedly watched the entire fight take place.

Grigorieva eventually fled the house with her children in tow, barefoot and in pajamas, Radaronline.com reported.

The battle between the couple has loomed large in recent months, as the 40-year-old Russian reportedly turned down a $15 million muzzle in May, that would have kept racist, curse-filled tirades on tape under wraps.

Pictures of Grigorieva with broken front teeth -- allegedly a result of Mel's boxing -- have also surfaced.