Teens, man accused of group assault

Three teenagers and a man accused of drugging and repeatedly sexually assaulting a young woman they met with at a pizza shop remain behind bars after their matters were briefly mentioned in Sydney courts.

Police allege the 18-year-old woman was given an unknown substance and repeatedly sexually assaulted after going to the shop at Lugarno, in Sydney's south, with a 17-year-old boy she knew in October last year.

It is alleged 38-year-old man Ricardo Audish, a 15-year-old boy and another 17-year-old boy, who were all known to the woman's teenage friend, met them at the shop and later took part in the assaults.

The woman was dropped off in a Riverwood street several suburbs away from where she was attacked and found by a passer-by, police say.

NSW Ambulance paramedics treated the woman at the scene before taking her to Liverpool Hospital, where staff called police.

The teens and man have all been charged with aggravated sexual assault in company and did not apply for bail when their matters were heard in various courts on Friday.

The teenagers, who cannot be named, are due to appear via video link in Parramatta Children's Court on Monday.

Audish is expected to appear in Central Court in March.