Japan's nuclear regulator will increase its number of legal staff from this spring to deal with lawsuits related to the Fukushima crisis, sources close to the matter said Wednesday.

The secretariat of the Nuclear Regulation Authority will increase the number of staff at an office in charge of litigation to 22 in the fiscal year starting in April from the current 17. In fiscal 2012, when the body was launched, it only had five employees, the source said.

The secretariat said it was handling a total of 45 lawsuits as of March 1, of which 29 had been filed by over 10,000 plaintiffs nationwide including evacuees and victims of the Fukushima accident who are seeking damages from the state.