Police raided an Osaka trading company Thursday on suspicion it has been illegally exporting medicines to North Korea since 1997, police said.

Yuko Boeki, based in Osaka's Chuo Ward, sold and exported 204 boxes of medicine to a North Korean company without proper authorization between September 1997 and February this year, police alleged. The medicines, which were sold for a total of 2.5 million yen, were designed to treat rheumatism, hypoproteinemia and to increase brain metabolism, police said.

Police also raided the homes of the company's executives in Osaka and Kobe, they said. The trading company usually handles electrical insulation materials bound for North Korea and China. Police acted on a tip that the firm was selling medicine abroad without the proper authorization required for selling pharmaceuticals. Investigators had been probing the firm for some time prior to the raid, sources said.