A Canberra teacher has denied having sex with a 15-year-old female student.
Derek Siddon, 31, a former music teacher at Canberra's Daramalan College, is facing 10 counts of having sexual intercourse with a person under the age of 16 after charges against him were upgraded.
The offences are alleged to have been committed in 2005.
He had initially been facing three counts of having sexual intercourse and five counts of attempting to have sexual intercourse with a person under 16.
Siddon pleaded not guilty to all charges at an arraignment hearing in the ACT Supreme Court on Tuesday.
Justice Richard Refshauge adjourned the matter for pre-trial directions on August 11, with a trial due to start on August 31.