Lai called the police and a manhunt was launched.

Lai was treated at Queen Mary Hospital and later discharged.

Initial investigations showed that the bus illegally crossed double white lines, then overtook and intercepted the victim’s car.

Officers believed the assault was the result of road rage, and had nothing to do with Lai’s political stance, as an outspoken opponent of Chief Executive Leung Chun-ying.

On Wednesday morning the suspect approached Lai at his office with an apology letter.

Lai, former chief editor of Capital magazine and former editor of Hong Kong Economic Journal, told media he was leaving the radio station in Cyberport Tower to go to a police station to give a statement on Wednesday when the man appeared at the reception desk.

Lai was astonished and he asked him whether he wanted to beat him again, but the man tried to pass him an envelope.

Suspecting it might be pay-off money, Lai rejected it, and reminded him it was illegal to offer him money.

The man, who claimed he was a new immigrant from the mainland and did not realise who Lai was, said it was an apology letter.

Lai did not take the letter and suggested that he surrender to the police.

Later the day, police confirmed a 34-year-old man had been arrested for common assault. He was released on bail and must report back next month. Officers at Happy Valley division were investigating.

Lai said his physical condition was fine and was no longer angry, but stressed that the case should be handled by the court so that people would understand there would be consequences for beating someone.

But he added that he would try to make a request for leniency to the judge.

The driver’s employer Kwoon Chung Bus told media the driver had been suspended and it would assist in the police investigation.