The chairman of the Federation of Thais Protecting the Monarchy group filed a lese majeste complaint with police on Thursday against a hot-tempered driver for remarks he alleges damaged the high institution.

Rachain Trakulwieng filed the complaint against Rach Wangitcharoensuk. He also asked that police charge Mr Rach with defaming the Thai people.

Mr Rachain handed over a video recording of Mr Rach's outburst and other evidence including photos posted on Facebook accounts.

He complained that Mr Rach's behaviour was unacceptable, and showed disdain for his compatriots and for the high institution.

Mr Rach has been in the news since Nanthawat Kamolrum posted photos and two video clips on his Facebook page, named To Jetdo, on Wednesday.

The two were involved in an accident in Thawi Wattana district of Bangkok on Wednesday.

Mr Rach, 24, was angry at Mr Nanthawat, 22, who was driving a pickup truck, and made abusive remarks about the country and the people.

"You're garbage," Mr Rach told Mr Nanthawat. "I never care about Thai people. I look down on Thai people," he said, as Mr Nanthawat asked him to move his Honda Civic so that it would not obstruct traffic.

At least twice in the two clips Mr Rach allegedly made negative remarks about the monarchy.

The clips went viral, one with 18 million views and the other almost 6 million as of Thursday afternoon. Mr Rach was heavily criticised on social media. Kasa Development, a real estate company, posted a Facebook message hours later saying Mr Rach had been fired. 

The matter did not end there. People went to the Buddha Monthon police station, where he was being questioned, on Wednesday night to see Mr Rach with their own eyes. The number grew to about 500 in the early hours of Thursday.

Police on Thursday released a video clip showing Mr Rach and his mother apologising to the people.

"I would like to apologise to everybody," Mr Rach said. "I may have said something that slipped off my tongue."

His father and mother said earlier that their son suffers from depression. He studied overseas and lacked understanding of Thai culture, they added.