The attack shocked Cambodia and sparked a national debate about justice in a country where wealthy people often act with impunity and buy their way out of trouble.
In the grainy black and white video, former TV presenter and actress Sasa was apparently seen being dragged from a sofa and then beaten up in a restaurant in the capital Phnom Penh.
The actress put the security camera footage online, but it is unclear how she obtained it.
Sasa, 28, said she was protecting a friend from the drunken advances of Sok Bun, when he became violent.
In the attack that lasted about a minute, he apparently punched and kicked Sasa in the face and his bodyguard allegedly pointed a pistol at her.
Sok Bun, 37, left the country after the footage began circulating on the internet last week.
Police said they believed he fled to Singapore, and Interpol issued a Red Notice calling for his arrest.