Man pleads guilty after 'marrying' 12yo

A man charged with having sex with a 12-year-old girl whom he "married" in NSW is set to be sentenced next year.

There was a long silence at Sydney's District Court on Friday when the 27-year-old, who cannot be named, was asked to stand and formally enter a plea.

The man has been charged with having sexual intercourse with the girl on at least three occasions between January 11 and February 5 this year at Raymond Terrace in the Hunter and elsewhere in NSW.

After he failed to get a response from the man, Judge Norman Delaney said: "I will ask the question again, `How do you plead, guilty or not guilty?'"

"Guilty", the man eventually replied through an interpreter.

Police allege the man married the girl in an Islamic ceremony in January.

His "bride" has since turned 13.

The girl's father has also been charged over the "marriage", with the court hearing the 27-year-old is due to give evidence at a trial into the matter next year.

The man has had his student visa cancelled and is now in immigration detention in Villawood.

He is set to face sentencing proceedings in February next year.