A cognitively impaired girl has required surgery after allegedly being sexually assaulted by a Sydney man she met online.
Paramedics treated the 15-year-old in Sydney's northwest before she underwent surgery at The Children's Hospital at Westmead on Sunday night.
"Inquiries revealed the girl met a man on social media and the pair had been communicating for a period of time before he arranged to meet her yesterday, and sexually assaulted her at a home in Sydney's northwest," police said.
A 20-year-old man was arrested in Toongabbie about 12.40am on Monday.
He was charged with two counts of aggravated sexual assault of a person under 16, two counts of aggravated sex assault with a person with cognitive impairment, and intentionally sexually touching a child aged between 10 and 16.
The man faced magistrate Fiona McCarron on Monday at Blacktown Local Court, where he did not apply for bail and it was formally refused.
He will next appear at Blacktown Local Court on January 11.