A university student's uncle is accused of stripping, binding and stabbing her before dumping her body in a NSW blowhole.

Derek Barrett, 27, is accused of murdering Chinese university student Mengmei Leng, also known as Michelle, before the 25-year-old's naked body was found floating in water at Snapper Point, on the Central Coast, in April.

Police allege they found images taken by Barrett on a mobile phone of Ms Leng without any clothes on as her wrists were tied up with duct tape, The Sydney Morning Herald reported.

A strap of tape was also placed over her mouth.

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Derek Barrett (left), 27, is accused of murdering Chinese university student Mengmei Leng (right) before the 25-year-old's naked body was found floating in water at Snapper Point, on the NSW Central Coast, in April

Other details of Ms Leng's last moments alive also emerged as Barrett faced Burwood Local Court on Wednesday where extra charges were laid including five counts of commit act of indecency, 17 acts of film persons private parts without consent and two counts of install device to film.

He also faces a charge of detain for advantage and two counts of filming a person in a private act without consent.

The new charges have been introduced after police allege Barrett took photos of a child as she slept, and took footage of himself masturbating over her and Ms Leng on different occasions before the 25-year-old died.

The discovery of Ms Leng's body, which was found with up to 30 stab wounds, made national headlines after NSW Police launched an appeal for her identify.

Detectives laid the extra charges against Barrett including five counts of commit act of indecency and 17 acts of film persons private parts without consent in case of Ms Leng's (pictured) murder

In May, the 25-year-old's mother, Mei Zhang (right), said she was unable to comprehend her daughter's death

In May, the 25-year-old's mother, Mei Zhang, said she was unable to comprehend her daughter's death.

'The time will never turn back to when Mengmei and I were living happily with each other,' she said through a translator in Sydney.

'You can never imagine how painful it is to me. The saddest thing in life is losing someone you deeply love.'

Mrs Zhang's husband died in 2008, leaving just she and her daughter, also known as Michelle, to depend on each other.

Ms Leng left her home in Chengdu five years ago to study at the University of Technology Sydney.

'Mengmei had always dreamed of being here to study,' her mother said, adding that her daughter was a feeling and understanding girl.

Barrett is married to Ms Leng's aunt who the student was living with in Sydney.