Perth grandmother Donna Nelson will remain in a Japanese prison after losing her appeal to overturn a six-year drug trafficking sentence.

Nelson has maintained her innocence and insisted she was the victim of an online romance scam.

Nelson has been told she has 14 days to launch an appeal to the Supreme Court.

The judges in the Tokyo High Court took about 40 minutes today to hand down their decision, which upheld the original judgement.

They argued none of the defence arguments were valid as Nelson had raised complaints to her online lover in the past and it could not be said that she blindly trusted him.

They said the 59-year-old decided to comply with his requests to bring a suitcase to Tokyo’s Narita Airport in January 2023.

Australian ambassador to Japan Justin Hayhurt was in the courtroom as the decision was handed down today.

“Australian officials have been supporting Ms Nelson and her family throughout this legal process and we will continue to provide that support,” Hayhurt told 9News.

Last year Nelson was sentenced to six years behind bars.