Phnom Penh - The son of a prominent Cambodian businessman was arrested on suspicion of beating a toll booth operator who demanded a standard 25-cent fee, a news report said Thursday.

Pao David, the son of tycoon Khy Pao, was arrested Tuesday after the beating at a toll road in the Cambodian capital, the Phnom Penh Post newspaper reported.

The reported victim, Pin Ratana, said the incident occurred after the 23-year-old drove through a toll gate. After he asked the man to return to pay the fee, Pin Ratana said he was attacked.

'He stopped his car and then used a big tube and the wrench from his car to hit me several times on my right shoulder, my right hand and my thumb,' he said, adding that Pao David hurled the wrench at him as he fled.

'He threatened that he would use the gun from his car to shoot me,' Pin Ratana was quoted as saying.

Rights activists regularly complain that Cambodia's rich enjoy virtual impunity from prosecution.