A "depraved" former teacher jailed for 20 years for raping runaway teenage boys has had an appeal against his conviction thrown out.

Graeme Andrew Joblin, 56, groomed vulnerable young boys he met while busking in Christchurch city centre.

He plied them with alcohol and drugs before taking advantage of them by raping and indecently attacking them.

In 2012, he was jailed for 20 years at Christchurch District Court, with a minimum non-parole term of seven years, after being found guilty by jury on 23 charges.


Judge Farish told him: "This offending could be described as depraved in the extreme".

In a decision released today, an appeal against his conviction was dismissed by the Court of Appeal.

Joblin claimed a miscarriage of justice after claims he did not receive a fair trial.

He alleged his lawyer at the time was lacking in preparation ahead of his trial, and then failed to call witnesses and failed to prepare written submissions or adequately argue various points of law.

But the claims were thrown out by appeal judges who found there to have been no miscarriage of justice.

The court heard that Joblin's victims, all boys, were aged between 13 and 17 when he preyed on them.

One victim said in a victim impact statement that Joblin had abused him while he was a pupil at a Wellington school where Joblin was an English teacher in the late 70s and early 80s.

Joblin later moved to Christchurch where he sexually assaulted eight at-risk boys while busking in the city centre.