Tweet Facebook Mail Warning: This story contains details and content that some readers may find distressing. A mathematics tutor isolated young girls in their family homes so he could molest them, a judge has heard. Quy Huy Hoang is accused of sexually abusing four girls while tutoring them in their south-west Sydney homes between May 2011 and July 2014.

Assisted by a Vietnamese interpreter, the 76-year-old pleaded not guilty to four counts of sexual intercourse with a child under 10 and four counts of indecent assault of a child under 16 at Sydney's Downing Centre District Court today. READ MORE: Construction to start on luxury $3.8 billion housing development in Perth The tutor was arrested at a Catholic church service in August 2014.

(Fairfax Media) Hoang abused the trust that three families had placed in him to teach their daughters, crown prosecutor Alex Morris said during openings in the judge-alone trial. Between May 2011 and March 2013, he allegedly molested two sisters, one of whom was aged between three and five years old and the other between six and seven. After experiencing multiple family tragedies, the girls' mother received a call saying Hoang heard of their plight and wanted to help.

He tutored the sisters free of charge, initially teaching the girls in the dining room but then persuading their mother it would be quieter in the toy room of their home. READ MORE: Police investigate Canberra Raiders star Josh Papali'i over an incident He pleased not guilty thro.