Police have hunted down a 79-year-old man suspected of raping a mentally handicapped teenager in a stairway inside a public housing estate in Hong Kong’s Fanling district.

The girl is reported to be 19 years old, with mild intellectual disability. She lives in a care center and only returns home at weekends.

The rape is believed to have taken place last Sunday when the suspect – a resident of the Cheung Wah Estate in the Northern New Territories, followed the girl into one of the estate’s lifts and started groping her.

According to Apple Daily, the man planned to take the girl to his home, offering mooncakes as a goad, but then led her into a staircase instead as his wife was at home.

Police have learned that the girl’s mother, who was going to work, left her in the estate’s playground, where the suspect first saw the victim.

Orient Daily reports that care center staffers noticed the girl was in a trance the next day and called the police, fearing she had been sexually assaulted.

Police soon tracked down the suspect after viewing CCTV footage from the estate.

The man faces one charge of rape and will appear in Fanling Magistrates’ Courts this Friday.

In February, a 75-year-old man in West Kowloon was arrested for raping his 12-year-old daughter.