Japanese police have arrested 25 suspected members of a fraud ring onboard an aircraft bringing them back to Japan from Cambodia.

Investigative sources say the men, aged in their 20s to 40s, are suspected of swindling a woman in Hokkaido, northern Japan, through a phone scam.

The men arrived at Tokyo's Haneda Airport late Wednesday and have been since been transferred to a police station near Tokyo.

Police say the group swindled nearly 3,000 dollars from the woman in her 70s in Hokkaido, falsely claiming she had won the right to move into a nursing home. They say the group tricked her into paying cash to resolve what they said was a dispute with the nursing home in question.

The men are believed to have separately entered Cambodia between March and August. They placed calls to potential victims in Japan, mainly elderly people, from an apartment that served as their hub.

Cambodian authorities detained the men in September.

Police say multiple passports were found bundled in the apartment, suggesting they were confiscated so the men could not flee the country.

They say the men are suspected to have been involved in similar fraud cases in at least eight prefectures that netted over 1.5 million dollars. They aim to unravel the whole picture of the group's scheme.