An elderly doctor who has been detained in the United Arab Emirates since August, had his court case postponed for the 15th time.

Professor Cyril Karabus, from South Africa, has been sitting in the court's lobby with his lawyers since the trial was delayed again on Monday.

Michael Bagraim, the Karabus family lawyer, said he had "just spoken to Professor Karabus - he's going back to the court again tomorrow.

"There's no news - just frustration. [Last week] the judge told the attorney-general to come up with the evidence and make a decision."

The trial has been postponed 15 times because the prosecution still "cannot find" the supposed incriminating file.

Professor Karabus was convicted in absentia of manslaughter by a UAE court more than 10 years ago. The prosecution claimed that in 2002 the doctor, who had previously worked in the UAE, had mistreated a terminally ill Yemeni girl who had leukemia.

Professor Karabus, unaware of his conviction, stopped off in Dubai on August 18 this year as he travelled back to South Africa from his son’s wedding in Toronto.

The 78-year-old doctor has been in detained in Abu Dhabi since then.

Since he was released on bail from prison in October, the professor's health has improved and he is "feeling more positive," confirmed Mr Bagraim.