Heritage shopping mall
The schoolgirl stole a £3m diamond necklace from a shop in Hong Kong's Heritage shopping mallWikipedia

Hong Kong police are hunting a gang of thieves who apparently used a young schoolgirl to steal a £3m diamond necklace, while her adult accomplices distracted jewellery store staff.

The group – two women and a man aged 30-40, and a young girl aged 12-14 – entered a jewellery store inside Heritage shopping mall. The adults were all well-dressed and spoke China's official state language, Putonghua.

Whilst the three adults distracted staff by asking to look at items on sale, the girl is thought to have taken a key from a drawer and used it to open a cabinet where the 100-carat gold necklace containing over 30 diamonds was displayed on a bust.

Having slipped the HK$36m (£3.01m) necklace into her pocket the necklace the girl is thought to have coolly left the store, quickly changed her appearance and got into a cab. The girl, described as slimly-built, 1.4 m tall, wearing dark jeans, grey hooded top and black shoes, was filmed on CCTV after leaving the store.

schoolgirl thief
The girl, aged 12-14, was captured on CCTV after leaving the store with the necklaceSource: Hong Kong Police

The girl, described as slimly-built, 1.4 m tall, wearing dark jeans, grey hooded top and black shoes, was filmed on CCTV after leaving the store.

Staff didn't notice the absence of the necklace until shortly before closing the shop. A police source told the South China Morning Post that the heist appears to have been well planned.

"Initial investigations suggest the girl stole a key from a drawer and then opened a display cabinet to steal the necklace when the three adults – one man and two women – kept staff busy," said the source.

The source added that this was the first such heist using a child in recent times.

"The necklace was embedded with more than 30 diamonds totalling about 100 carats. We were told it was worth about HK$36 million. The three adults posed as big spenders and demanded employees show them jewellery in an apparent move to divert staff attention."

Police believe the gang may try to escape from Hong Kong to the mainland and border officers are on alert.