The government demanded Tuesday that Paloma Industries Ltd. resubmit a report within a week on its probe into deadly carbon monoxide poisonings caused by defects in its gas water heaters.

The Ministry of Economy, Trade and Industry said it found insufficient accounts in the report the Nagoya-based manufacturer submitted Monday, and sought clarification and additional data on 30 items.

For instance, Paloma reiterated at a news conference Monday that it never instructed improper alterations to be made to its products.

But Paloma made no mention of that in the report, METI said, urging the firm to back up the assertion.

Of the 28 accidents, Paloma said nine were caused by improperly altered safety devices coupled with dirty heat exchangers and deterioration of parts.

METI also demanded a detailed account from Paloma on why it neglected to inform users of the unauthorized alteration, even though it had issued warnings on the matter internally and vis-a-vis business partners.

The ministry urged Paloma to provide the manufacturing dates of the water heaters involved in the accidents and other data.

A total of 21 people in eight prefectures died and more than 30 were injured in the poisonings, Paloma said.

The company launched an in-house investigation soon after the issue hit headlines in mid-July.