Australian embassy officials in Myanmar have been kept out the courtroom where Sydney economist Sean Turnell has appeared on charges of violating the country's official secrets act, raising more doubt about whether he will receive a fair trial, ABC news reported.

Professor Turnell, 57, was working as an adviser to Aung San Suu Kyi before her government was toppled by the military in a coup in February. He was arrested five days after the military seized power and was later accused of trying to flee the country with "secret state financial information".

The Australian appeared in a court in Myanmar's capital Naypyidaw last Thursday and hearings have now been scheduled weekly. But in a development that has concerned Australian officials and Professor Turnell's supporters, no consular officials have been allowed to observe proceedings.