His niece was just nine years old when he first molested her in 2014, and he went on to outrage her modesty about 10 times a year until 2017.
He stopped targeting the girl when she started menstruating, the court heard.
The 22-year-old Singaporean pleaded guilty on Friday (April 8) to three molestation charges.
Three other charges, including two more counts of molestation, will be considered during sentencing.
He cannot be named due to a gag order to protect the victim’s identity.
Deputy Public Prosecutor Tin Shu Min said the girl and her uncle lived together in a flat with other family members.
They shared a bedroom with her brother.
The girl, who was sleeping in the room some time in 2014, woke up when her uncle carried her to his bed and molested her.
On one occasion in 2015, she was sleeping in her mother’s room when she woke up, as her uncle had again carried her to his bed. He then molested her. She was 10 at the time.
After that, he carried her back to her mother’s room.
The court heard that he molested the girl yet again in 2017, when she was 12.
The DPP said: “The accused stopped the acts in 2017, when the victim started menstruating.
“The victim’s relationship with the accused improved in 2019 when the accused started to chat with her and her younger brother about school and life and the victim stopped resenting him as much.”
The man’s offences finally came to light in 2020 when the girl’s stepfather confronted her over some messages which she had sent to her former boyfriend.
Court documents do not disclose details about the messages but the victim burst into tears and told her stepfather about what her uncle had done to her.
The stepfather accompanied her to lodge a police report on May 30 that year.
On Friday, the court called for a report to assess the offender’s suitability for probation.
He is expected to be sentenced on May 20.
For each count of molesting a child below 14 years old, an offender can be jailed for up to five years and fined or caned.