Cops are searching for MMA fighter Luke Cummo — who was featured on “The Ultimate Fighter” — after he got into a domestic dispute with his ex-wife stemming from a custody battle between over their two boys, sources told The Post.

Luke Cummo, 33 — who has been posting photos of himself on Instagram while cops scour the area looking for him — allegedly sent email threats to his ex-wife, the sources said. Nassau police responded to his home in Valley Stream earlier today with a warrant out for his arrest and are actively searching for the MMA fighter, sources said.

According to a friend, Cummo has been spiraling out of control and is currently going through a custody battle over their twin-boys with his estranged ex-wife. “He’s acting stranger and stranger. If you see his Facebook, you can see some weird stuff. He still trains people but a lot of his MMA brethren have stopped talking to him. He quit fighting, lost his job with the UFC,” after a DWI conviction in 2007, the friend who refused to have his name published said. “He’s really losing it.”

Cummo, who now teaches mixed martial arts to children, was featured on “The Ultimate Fighter” during Season Two.

He was a striking coach in Garden City and taught muay thai, a form of martial arts, to aspiring fighters.

He posted to Facebook today around 10 a.m. wearing a pair of head phones and a cap plastered with the phrase “My ego,” along the front.

He also posted the same photo to Instagram [LukeCummo13] around the same time. His Instagram summary is titled “T.E.A.M. Captain; I bring the ruckus!”

He accepted friend requests on both social media sites as cops are still searching for the mixed- martial artist.

Cummo, a biology buff, brags about drinking his own urine on www.mixedmartialarts.com and said “I drink as much as I can as often as I can.”