A Japanese lawmaker facing drug charges punishable by death has pleaded not guilty in a Chinese court, Chinese state media reports.

Takuma Sakuragi, a 71-year-old member of the Inazawa municipal assembly in Japan's Aichi prefecture, was taken into custody on October 31 when staff at the Guangzhou Baiyun International Airport found more than 3kg of methamphetamine in his suitcase, Xinhua reported.

Sakuragi was preparing to board a flight to Shanghai en route back to Japan when he was stopped, the state-run China Daily reported.

After his arrest, he denied trafficking drugs, saying he was taking the luggage to Shanghai for a friend, the report continued. Two others -- Aly Yattabare, from Mali, and Guinea citizen Mohamed Soumah -- were arrested in relation to the case and are also standing trial.

On Tuesday, Sakuragi pleaded not guilty in the Guangzhou City Intermediate People's Court to charges of transporting illegal drugs.

The indictment against him claimed the politician flew from Nagoya to Guangzhou two days before he was detained last year, checking into a hotel with the help of a Nigerian named as Gemadi Hassan, the South China Morning Post reported.

He testified that he made the trip after extensive email communication with Hassan, who promised to help Sakuragi recoup hundreds of thousands of dollars of losses in Nigerian investments if he signed a document in Guangzhou, the newspaper reported.

The indictment continued that Yattabare gave Sakuragi a suitcase containing women's platform shoes to give to a third party in Japan. Airport security staff subsequently found 28 bags of methamphetamine inside the soles of the shoes and in the suitcase's handle, weighing 3.28kg in total, the South China Morning Post reported.

If found guilty, Sakuragi could face the death penalty, which can be applied under Chinese law in cases involving seizures of 50 grams or more of methamphetamine or heroin. An unidentified 50-year-old Japanese drug trafficker was executed on July 26 in the northern Chinese city of Dalian, China Daily reported.

While Japan has the death penalty on its books, it is not applicable for drug crimes.

Yoshihide Suga, Japan's chief cabinet secretary, told reporters in a press conference in July that the Ministry of Foreign Affairs would provide whatever support was needed by Sakuragi, as it would to all Japanese citizens.

But he added that drug crimes were punished severely not only in China but in the wider international community.