Court dismisses teacher's child sex appeal

An Adelaide high school teacher, jailed for 10 years for having oral sex with a female student, has failed in a bid to have his conviction overturned.

Marco Chiro, 56, was jailed in July for the sexual exploitation of a student between 2008 and 2011 while he taught at Norwood Morialta High School.

Chiro appealed against both his conviction and sentence, arguing the jury's verdict was unreasonable and the jail term excessive.

But both appeals were dismissed in the South Australian Court of Criminal Appeal on Wednesday.

"In my view the sentence imposed was not manifestly excessive," Justice Ann Vanstone said.

The court heard Chiro was in a position of authority when he engaged in sexual activity with the victim on several occasions.

Justice Vanstone said he started the relationship with hugs after class and flirtatious emails before steadily increasing the intimacy over time, which suggested he was "grooming" the student.

"There was a clear intention to cultivate (the victim's) affection," the judge said.

Chiro will serve a minimum of six years in prison.