Lethal Weapon 5? Mel Gibson Accused of Gun Threat Against Oksana Grigorieva

In what is quickly becoming an uglier feud by the day, Oksana Grigorieva has apparently told Sheriff's deputies Mel Gibson threatened her - with a gun.

The L.A. County Sheriff's Department is investigating the actor for alleged domestic battery, assault with a deadly weapon and child endangerment.

The investigation is based on the following:

Domestic Violence: Oksana alleges Mel punched her in the face twice, knocking out a tooth and chipping another one. Mel's lawyers deny this.
Assault with a Deadly Weapon: Oksana told deputies Mel threatened her with a handgun at his Malibu home, an allegation based on her word.
Child Endangerment: Oksana claims that on January 6 of this year, Mel allegedly punched her in the face while she was holding their daughter.
There was also that racist, sexist tirade.
As we reported earlier today, Mel's lawyers will likely present evidence to deputies that Oksana made up some of the stories and tried to extort him.

He is expected to allege that she has demanded cash in return for secret, recorded tapes of their explosive arguments, some of which were leaked.

According to TMZ, Mel's lawyers will meet with officials to argue Mel is innocent of any crime against Oksana Grigorieva, and the victim of extortion.

The website also claims Mel's lawyers will present evidence that Oksana lied to Sheriff's deputies by knowingly making numerous false statements.

The Sheriff's Department will present the case to the L.A. County D.A.'s office for felony review ... probably in two weeks.