Wednesday Oct 12 18:52 AEST

Lawyers for convicted drug smuggler Schapelle Corby have vowed to take her legal battle to Indonesia's highest court after a Bali appeal court cut only five years from her original 20-year jail term.

The Bali High Court shortened Corby's sentence on Wednesday to 15 years following a protracted legal appeal and several trial re-openings in the lower Denpasar District Court.

Lead lawyer Hotman Paris Hutapea said, "There is a verdict. They reduced by five years to 15 years."

Corby's family and high-powered legal team had been hoping the court would free the former Gold Coast beauty student, or at least slash her sentence for drug smuggling by 10 to 15 years.

Her sister Mercedes said the family was distraught and weighing up whether to tell Corby by phone, or wait until a regular visit to Denpasar's Kerobokan Prison on Thursday.

"She didn't do it, She should be free, I was expecting the Australian government to do something, we're not happy in this sentence and we will appeal immediately."

Hutapea said he had not been officially advised of the decision, which was made behind closed doors and delivered on paper without any court appearance by Corby.

Corby's next avenue of appeal is to the peak Supreme Court in Jakarta.

Mercedes Corby said she would immediately tell her mother Rosleigh Rose, currently in Bali, of the decision.

"I was prepared; mum wasn't," she said.

She accused Canberra of trying to hide the lax security situation at Australian airports and said letters to the federal government had gone unanswered.

"The longer she is here, the more people will forget about her. That's what they (the government) think," she said.

Corby supporters also condemned the appeal court's decision.

"It's absolute tokenism ... it's a pittance," said Schapelle Corby Support Group coordinator Rachelle Hamilton.

"I suppose they have to be seen to be upholding the Muslim or Indonesian way and she's been made to carry the can."

Hutapea said he believed the 15 years was "not too bad".

"But I hope we get a better result from the Supreme Court," he said.

However, he said he believed the prosecution in the case would also appeal against the Bali High Court's sentence reduction.

Another of Corby's legal team, Erwin Siregar, confirmed the cut in Corby's sentence and said they still believed she had a chance to be freed by the Supreme Court.

"We will request through the Supreme Court to allow a teleconference for testimony from new witnesses," he said.

Last month Corby's lawyers said they hoped to organise a video link from Australia to allow unidentified witnesses to present new evidence about who really owned the drugs, but they were unable to convince Bali's High Court they could find fresh witnesses.

Prosecutor Wiswantanu said there would be no teleconference, because the higher court would not allow fresh evidence in its deliberations.

"Judges in the Supreme Court will only examine the legal documents and there will be no new examination to look for more facts," he said. "There will be no new hearing after the High Court decision, so there will be no teleconference. It is impossible."

Meanwhile, Foreign Minister Alexander Downer said the federal government had done all it could to help Corby.

Mr. Downer said Corby's lawyers still had the option of appealing the decision in the peak Supreme Court of Indonesia.

"That really is a matter for them," he told reporters.

Mr. Downer said further intervention by the Australian government would have made no difference.

"The government couldn't have made a difference one way or the other, we could only make matters worse for Schapelle Corby by directly trying to influence the court."

A spokesman for Mr. Downer said Australia had not yet received official notification of the reduction in her sentence.