The trial of prominent Indigenous community figure Donna Nelson will begin in Japan next week.

The Ballardong Njaki-Njaki woman has spent 18 months in a Tokyo prison after being accused of smuggling drugs into the country.

In February it was revealed Ms Nelson would face court in the last week of June.

The West Australian reports the trial will start June 27 with a verdict expected on July 11.

Shinjuku International Law Firm paralegal Matthew Owens told The West on Friday that "Donna is busy preparing for the trial".

The former chair of the Derbarl Yerrigan Health Service was arrested at Narita Airport in Tokyo on January 4, 2023, after nearly 2kg of methamphetamine was allegedly found in her suitcase.

The 57-year-old had been detained in Japan for several weeks before news of her arrest emerged.

While Ms Nelson has received consular assistance from the Department of Foreign Affairs and Trade, it is understood her family has not been able to have contact with her since the day of her arrest and can only receive updates through her lawyers and the Australian embassy.

The West reports that only Ms Nelson's lawyers, a pastor and embassy staff are permitted to visit her in prison.

Ms Nelson's family has previously told media in Western Australia that she was offered a trip to Japan by a man who she met on an online dating app, calling himself Kelly, with whom she had been corresponding for two years, and was then approached by a man claiming to be an associate of "Kelly", who asked her to take a suitcase to him in Japan.

Ms Nelson's daughters said the Nigerian man told their mother he owned a fashion brand, sent her a photo of what he claimed was his Japanese residency card. He then purchased her business class flights to Japan, flying via Singapore, Laos and Vietnam.

It is understood she is held under strict conditions in Chiba Prison, being allowed out of her cell for only 30 minutes per day.

The Japanese legal system has severe penalties for drug importation and an extremely high conviction rate. Ms Nelson could face up to 20 years in prison.