Former Prime Minister Naoto Kan, who led the government's response to the Fukushima nuclear disaster in March 2011, said Wednesday he shouldn't be held criminally liable for the crisis, sources said.

Resident groups across Japan, mainly in Fukushima Prefecture, have filed complaints pressing for criminal charges to be levied against 40 people, including Kan and members of his Cabinet at the time, for alleged professional negligence resulting in injuries. But the former prime minister said in a document submitted to prosecutors through his lawyers that "there was no problem" with his immediate response to the then-unfolding meltdown crisis, the sources said.

The complainants have accused Kan and two of his ministers of failing to promptly order Tokyo Electric Power Co. to vent the reactors it was unable to safely shut down at its Fukushima No. 1 nuclear plant to lessen their internal pressure before hydrogen explosions injured workers.