A court controlled by the junta in Myanmar has sentenced Australian economist Sean Turnell to three years in prison.

This was confirmed by judicial sources on Thursday of the German Press Agency.

The former advisor to the ousted Prime Minister Aung San Suu Kyi was arrested shortly after the military coup in February 2021 and had to answer in court for violating a law on official secrets.

In addition to Turnell, Suu Kyi has also been sentenced to three more years in prison for the same alleged offence, the sources said.

Australian broadcaster ABC reported that representatives from Australia and the media were denied access to the courtroom in the capital, Naypyidaw.

Turnell, who has always denied the allegations, has been in the Insein prison in the city of Yangon (formerly Rangoon), which is notorious for its torture methods.

He is now being held in a prison in Naypyidaw.

The economics professor had previously lived in the Southeast Asian country for several years.

He worked as an advisor to Nobel Peace Prize winner Suu Kyi to support Myanmar's economic development.

Since the coup, the junta has ruled with violence and terror.

In recent months, Suu Kyi has been sentenced to a total of 20 years in prison for various alleged crimes, including corruption and incitement to riot.

Observers speak of show trials.

The 77-year-old politician has been in solitary confinement in a prison in the capital Naypyidaw since June.