In passing sentence District Judge F. G. Remedios said that sales manager Li Jiaqi, 24, had 'played a greater role' in the incident which left cabbie Edwin Yap Hock Seng, 58, with a broken nose and bruises on his face.

Mr Remedios added: 'He was the one who started the whole incident when the victim wanted compensation for his street directory.'

Li was sentenced to two months' jail, while his friend, private student Zhang Bing, 19, was jailed for a month.

Zhang wept when her sentence was passed while Li carried a half-smile even as police officers hauled both of them out of the district court.

According to court documents, Zhang arrived from China last January to study business administration at a private school in Geylang.

The incident happened on Oct 24 last year when Li and Zhang, along with Zhang's then-boyfriend Huang Bokai, 21, boarded a taxi along Orchard Road after drinking at a pub.

When they reached the basement of a condominium along Geylang Lorong 40, Li, who sat in the front passenger seat, started vomitting.

Mr Yap stopped his vehicle and Li got out to throw up. Zhang also got out to help him. It was then that Mr Yap noticed that vomit had soiled the interior of his taxi as well as his street directory.

He turned to Huang, who was still inside the cab, and demanded that he pay for it as it was company property.

Huang refused and alighted to join his friends.

When Mr Yap confronted them, Li threw the first punch. Huang and Zhang joined in.

A condominium security guard who heard Mr Yap's cries for help called the police. Mr Yap was later taken to Tan Tock Seng Hospital where he was warded for three days.

Huang left for China after the incident and has not returned to Singapore since.