Animal Planet Star -- Ex Claims Physical and Drug Abuse ... He Says BS

One of the stars of Animal Planet's "Battleground: Rhino Wars" just learned there's something actually more dangerous than a rhino ... a pissed off ex-girlfriend.

Azad "Oz" Ebrahimzadeh is under investigation by Memphis PD after Elizabeth Keister filed a police report claiming he punched and choked her during a trip to Australia last month. Law enforcement sources tell us since it happened outside of Memphis they can't do anything.

But Keister also claims she found drugs in his home he's possessing illegally ... ketamine and a bag with white powder, labeled "Viagra." Cops say they will investigate that charge.

But the Special Forces medic says she's full of it ... just a bitter ex who embarrassed him by getting wasted in front of his family during their trip. He denies striking her and says he has a DEA license for the drugs.

What concerns Oz most is his non-profit, VETPAW -- he says he doesn't want the allegations to jeopardize his work to protect African wildlife. He's considering his legal options against Keister.