Twenty-four people, most of them Brazilian nationals, have been arrested on suspicion of stealing generators and other equipment from construction sites in 13 prefectures in central and western Japan, police said Friday.
The total value of the stolen goods was estimated at about 1 billion yen, involving some 280 theft cases.
The theft ring is believed to have been operating since 2000, police said.
The group first stored the stolen items in Hyogo Prefecture, according to the Hyogo Prefectural Police, before smuggling them from Osaka or Kobe ports to destinations abroad, including Africa, Southeast Asia and Latin America.
Police said the group's activities first came to light after one alleged member, a 31-year-old Brazilian national, was arrested on an unrelated traffic violation incident in April 2002.
Since then, the Hyogo police have conducted joint investigations with police forces in nearby prefectures, including Kyoto and Fukui.
Generators made in Japan are apparently popular in developing countries like Africa, where electricity is often in short supply, police said.
Investigators raided several places Nov. 5, including a repository for the stolen items, in Sanda, Hyogo Prefecture.