A US judge has ordered a Queenslander accused of stalking to hand in his passport and refrain from using social media while on bail.

An Australian tennis coach accused of stalking his ex-girlfriend and threatening to post naked photos of her online has appeared briefly in a Chicago court.

Mark Terry Henderson, 32, who was was one of Australia’s top-ranked junior players in the late 1990s and then moved to the US where he played and coached at elite universities, was arrested in Tennessee and extradited to Chicago last week.

Henderson is accused of harassing his 29-year-old former girlfriend, who lives in Chicago, with phone calls, emails and texts, including threats to her life, after she broke up with him in February.

Henderson, who had been living in Brisbane, sent the woman a collage of naked photos and threatened to post it online if she did not send him more nude images, prosecutors allege.

Last month he allegedly flew to Chicago, waited out the front of the woman’s parents’ house, then grabbed and threatened her when she walked to her car.

A judge has granted Henderson $US500,000 bail.

He had to surrender his passport, refrain from using social media and undergo GPS monitoring.

Henderson is due back in the Chicago court on Thursday.

Henderson played tennis at the University of Tennessee and Illinois’ DePaul University and was a coach at Northwestern and Western Michigan universities.