The Australian professor has been detained for more than 19 months by Myanmar's military regime, charged with violating the nation's national security laws.

The federal government has consistently rejected the charges.

Foreign Minister Penny Wong said he has been "unjustly detained".

Senator Wong says Australian government officials were denied access to the court for the verdict after Prof Turnell was tried behind closed doors.

She said the government will continue to offer Prof Turnell and his family support "for as long as required".

"We will continue to take every opportunity to advocate strongly for Professor Turnell until he has returned to his family in Australia," she said in a statement following the ruling.

"We acknowledge the strong international support shown for him, including from our region."

His Australian-based partner, Ha Vu, said she and her family were "heartbroken" at the verdict and called for him to be deported.

"Sean has been one of Myanmar's greatest supporters for over 20 years and has worked tirelessly to strengthen Myanmar's economy. Please consider the contributions ... and deport him now," she said in a Facebook post quoted by Reuters.

Prof Turnell served as an adviser to former leader Aung San Suu Kyi before her elected government was ousted by a military coup in February 2021.

Suu Kyi also received a three-year prison sentence under secrecy laws, as did three of her former cabinet members.

Prof Turnell was charged on the basis of documents seized from him but the details of his offence have not been made public.

with Reuters

Australian Associated Press