Kiwi free-diver Ant Williams breaks second world record for deepest ice dive

Less than 48 hours after breaking the world record for the deepest dive under ice, Kiwi free-diver Ant Williams has done it again.

On Saturday (NZ time), Williams plunged 75m below the ice in northern Norway to beat the record he set on Thursday by five metres.

He broke the previous record by five metres two days earlier, when he swam down 70m.

"Today, I pushed deeper under the ice to reach 75m, surpassing my record from two days ago," he posted on his Facebook page.

"It felt fantastic today. The weather was perfect and I guess the pressure of reaching a record was over, so I just got to enjoy the dive.

"Overnight, I made some important tweaks to make the dive flow better for me. Absolutely pumped to have pushed the world record 10m deeper this week."

Williams said he would submit his videotapes to the Guinness World Records for official verification.

He wore a black armband to honour the innocent Christchurch shooting victims in his latest attempt.

His team had to dig through two metres of snow, before sawing a hole in the frozen surface of a Norwegian fjord. They then lowered a rope into the impenetrable blackness before he could dive down.

With nothing more than a wetsuit, goggles, a nose clip and a torch, Williams swam into darkness.

At this time of year, temperatures in northern Norway can drop into the negatives.

The 47-year-old, who now resides in Australia, has been free-diving for nearly 20 years and can hold his breath underwater for eight minutes.