Five government teams dealing with Japan's tsunami and nuclear catastrophes kept no detailed records, an official said Friday, adding to a growing picture of chaos in Tokyo's disaster response.

Earlier this week the government said the nuclear disaster task force that ordered tens of thousands of evacuations had no written record of its decision-making process -- an essential component of disaster management.

Now the government has admitted having no minutes from a further four emergency committees, an admission likely to worsen the view of Tokyo's response to the world's worst nuclear accident since Chernobyl.

The five emergency bodies include the main disaster headquarters and the disaster victims assistance team, as well as the nuclear disaster task force, which was headed by then Prime Minister Naoto Kan and included all of his ministers.

These three committees failed to keep even brief summaries of their meetings, while two other task forces have only partial summaries.

Such records are usually thought of as essential for careful and coherent planning to mitigate the impact of future disasters.

Several other emergency committees kept only summaries of their meetings, leaving blanks in the record of how top officials addressed the aftermath of the tsunami and the atomic accident it spawned at Fukushima as reactors went into meltdown, spewing radiation over a wide area.

Deputy Prime Minister Katsuya Okada has instructed ministers to create summaries of the meetings by the end of February, an official at the Cabinet Office said.

Okada plans to hold a press conference later Friday to explain how the government failed to keep the records, the official said.

Kazuhiro Hayakawa, associate professor of administrative law at Omiya Law School said the lack of a written record was "ridiculous" and almost certainly a contravention of the legal requirement to keep minutes.

"No matter how much of an emergency it was, it is absurd that they did not keep records of the meetings, which were no doubt subject to the Archive Management Law" requiring a written record, he said.

"I doubt it was intentional on the part of the government. But I suspect government officials lacked a clear chain of command to order the creation of the records.

"This failure has deprived us of the possibility of studying what exactly happened" immediately after the disaster, he said.

Opposition parties leapt on the admission, calling it an example of the inexperience of the ruling Democratic Party of Japan.

"This is symbolic of the recklessness of the government," said Hirofumi Nakasone of the leading opposition Liberal Democratic Party.