Dragons lock Jack de Belin.

St George Illawarra forward Jack de Belin has been charged with sexual assault following an alleged incident in Wollongong on Sunday.

The 27-year-old was charged with one count of aggravated sexual assault in company on Thursday, and has been granted bail to appear in Wollongong Local Court on Tuesday, February 12.

De Belin, who made his State of Origin debut for NSW this year playing in all three games for the Blues, was interviewed by police in Wollongong on Wednesday afternoon.

An NRL spokesman said the Dragons had informed the Integrity Unit about the incident involving the 154-game veteran and the league would now allow the legal process to take its course.

The Dragons released a statement confirming the charge on Thursday night.

"The St George Illawarra Dragons have today been advised that forward Jack de Belin has been charged with sexual assault following an alleged incident in Wollongong on Sunday, December 9," the statement read.

"The club is taking the matter very seriously and have been working with Jack and all relevant authorities, including the police and the NRL Integrity Unit, since this time.

"Jack has been provided with welfare support to enable him the time and opportunity to deal with the matter.

"As this is a police matter to be considered by the court, the club is not in a position to make any further comment at this time."