Seven teenagers in Hong Kong have been sentenced to either probation or detention for up to three years for beating and sexually assaulting a 14-year-old girl.

One defendant, a 14-year-old girl, was sent to a rehabilitation centre for up to nine months on Wednesday, while six others were earlier sentenced over a variety of offences in connection with the attack. An eighth defendant has also pleaded guilty to charges of assault occasioning actual bodily harm, indecent assault, theft and criminal damage.

Kowloon City Court earlier heard the victim had sex with one of the defendants, 18-year-old student Fu Chi-kuen, at a hotel in Tsim Sha Tsui in the early hours of August 20 last year, after losing a game with her newly met friends.

Later in the afternoon, the victim was taken to another nearby hotel, where she was attacked and humiliated by seven girls. They smashed her mobile phone and stole HK$8,000 from her.

Police subsequently determined one of the girls involved in the assault had grown jealous of the victim.

A medical examination revealed the victim had multiple bruises and scars on her head, neck, chest and limbs.

Fu was arrested the next day. The seven girls were apprehended between August 20 and 21.

He claimed that the sex was consensual and he did not realise the victim was underage.

Student Yuen Tsz-yan, 17, admitted asking the victim to have sex with Fu and urging the others in the group to attack her. Yuen said she had a crush on Fu and thought that the victim had stolen her sweetheart.

Hon Wai-ting, who was 18 and jobless, and five other girls who cannot be named for legal reasons, admitted attacking the victim by beating her, slapping her, kicking her, pulling her hair and pouring liquids on her.

Some of the defendants sexually assaulted and urinated on the victim, as well as forcing her to commit an obscene act on herself.

One teen stole HK$8,000 from the victim and smashed her iPhone on the ground during the assault.

The 14-year-old girl sentenced on Wednesday had also beaten the victim and asked her to lick the bottom of her sneaker.

The assault was videotaped by a 13-year-old girl, whom police have not yet identified. The footage was later found on the mobile phones of Yuen and another 15-year-old defendant.

At Kowloon City Court last month, Fu was sentenced to a rehabilitation centre for unlawful sexual intercourse with a girl under 16.

Yuen was ordered to serve up to three years in a training centre on charges of procuring unlawful sexual intercourse, assault occasioning actual bodily harm, and possessing and publishing child pornography.

Hon was ordered to serve up to three years in a training centre for assault and inciting a child to commit a grossly indecent act.

The five anonymous defendants pleaded guilty to assault. One of them also admitted to indecent assault, theft and criminal damage.

A 14-year-old girl was sentenced in July to a rehabilitation centre, whereas another 15-year-old girl was put on probation for two years involving supervision and counselling.

A third 15-year-old also received a two-year probation, but she must spend the first nine months in a correctional facility.