The public submissions process for the inquiry into the fatal Tauranga landslides has been extended for another three weeks.

A government inquiry was launched in February into the January landslides, which killed eight people.

Six people died at Mt Maunganui Mauao when severe storms and record rainfall sent mud and debris onto the campsite below. A landslide also fell onto three properties in Welcome Bay Road in Pāpāmoa, killing a further two people.

The inquiry chair, former Supreme Court judge Sir Mark O'Regan, said the inquiry had already received a high calibre of submissions, and further contributions were welcome.

"We have received thoughtful and informative submissions from people with a wide range of knowledge, experience and perspectives," he said.

"Those submissions are already valuable in helping the Inquiry build a fuller picture of the circumstances surrounding these tragic events and the lessons that can be learned from them. Extending the submissions period will allow more people to share information that may assist the Inquiry's work."

The inquiry has been tasked with investigating how the landslides occurred, and whether relevant agencies took appropriate steps to manage any risk.

Submissions will now close on 4 September. Video and drone footage, photos, rain gauge measurements, and information relevant to the Inquiry's terms of reference could be uploaded to a portal.

A police and coronial process is also underway, and the Tauranga City Council and WorkSafe have also commissioned their own investigations.