Police have charged a man with the murder of a Chinese international student whose body was discovered floating face down in a blowhole on the NSW central coast last weekend.

Michelle Leng, 25, was reported missing by her family on Anzac Day after it was claimed she failed to return to her Campsie home from a shopping trip four days earlier.

On Friday afternoon, NSW homicide detectives arrested 27-year-old Derek Barrett, who is Ms Leng's uncle, at Campsie Police Station. He was later charged with her murder.