(CNN) An Australian woman has been sentenced to death by hanging after a Malaysian court overturned an earlier acquittal of drug smuggling charges.

A three-judge panel unanimously threw out the previous ruling in 54-year-old Maria Elvira Pinto Exposto's case, her lawyers told CNN.

"An appeal will be filed in the Federal Court -- the final appeal," lawyer Muhamed Shafee said, who added his client was "a strong person."

The grandmother and mother of four was arrested in December 2014 while transiting through the Malaysian capital Kuala Lumpur on a flight from Shanghai to Melbourne.

She was found in possession of 1.1 kilos (2.4 lb) of crystal methamphetamine and faced a mandatory death penalty under Malaysia's draconian drugs laws.

Read More