A 17-year-old boy who kicked a policeman in the face must serve another three months in youth detention, after a County Court judge increased his penalty on appeal.

The teenager, who cannot be named, this year spent 30 days on remand for the attack at Highpoint Shopping Centre on Boxing Day last year but was spared further time in custody after he was sentenced, and avoided a conviction, in a decision that outraged police.

The police officer assaulted while making an arrest at Highpoint Shopping Centre. Credit:Police Association

Prosecutors appealed against the decision made by a children’s court magistrate and on Thursday a judge ordered the youth spend four months in detention and imposed a conviction. The 30 days counts as time already served.

‘‘This assault involved the intentional infliction of injury, aggravated by the fact that the victim was a police officer who was doing no more than his duty,’’ the judge said.