Tokyo police conducted nationwide raids on an insurer serving pro-Pyongyang Korean residents of Japan Sunday on suspicion that it concealed assets to foil debt collection by the state-backed Resolution and Collection Corp., investigative sources said.

Affiliated with the General Association of Korean Residents in Japan, a pro-Pyongyang group known as Chongryon, Tokyo-based Kongo Hoken is suspected of withdrawing deposits from its bank accounts around the end of 2016 to prevent their confiscation by the collection agency, the sources said.

The RCC has been trying to collect loans it bought from 16 failed pro-Pyongyang credit unions, including ¥1 billion ($8.9 million) extended to Kongo Hoken from the now-defunct Chogin Tokyo credit union.

Established in April 1977, Kongo Hoken has about 30 branches across the nation and employs more than 100 people, according to publicly available legal documents and sources familiar with the insurer.

In the late 1990s, many pro-Pyongyang credit unions went bankrupt and RCC agreed to shoulder their nonperforming loans.

The RCC filed a lawsuit against Chongryon in November 2005, seeking the return of ¥62.7 billion ($557 million) in nonperforming loans the RCC had taken over from the failed credit unions after finding that the recipients of that money had handed it over to Chongryon.

In June 2007, the Tokyo District Court ordered Chongryon to repay the ¥62.7 billion as demanded to the RCC. However in June this year, the RCC filed a fresh suit against Chongryon after it failed to repay ¥57 billion of the sum.

In the suit aimed at evading the 10-year statute of limitation on the loans, the RCC demanded that Chongryon pay ¥91 billion, including interest, a request that was wholly accepted by the district court in August.

If this ruling is finalized, the statute of limitations will be extended by another 10 years.