A French tourist who died in a hot pool at Rotorua's Polynesian Spa was seen by a staff member face down in the pool but no one immediately pulled him out.

An inquest into the death of Denis Miklus was held in the Coroner's Court in Rotorua today before Coroner Gordon Matenga.

Miklus, 67, was found dead in the Priest Pool about 1pm on June 19, 2018.

His partner of 29 years, Jany Toomaru, had dropped him at the pools while she did shopping.

Duty manager Kauljeet Kaur told the inquest Miklus and two other customers were the only people in the pool at the time.

While doing her checks, she noticed Miklus' body floating under the water with his hands clasped near his stomach.

Denis Miklus died in a Polynesian Spa pool in 2018. Photo / Supplied

Kaur said she thought he was doing exercises and didn't want to disturb him.

She initially said she left him for about two minutes before checking him again. When she went back she realised something was wrong and alerted lifeguard, Elly Tibus.

Kaur later gave an additional statement to police to say it was actually about 40 to 50 seconds later and she had initially got her timing wrong as she was in shock when giving her statement.

When she approached him again, she said "hello hello" but Miklus didn't respond.

"His lips were blue, his tongue was out and his body was white."

In Kaur's additional statement she said she hadn't gone to Miklus immediately when seeing him under water as she had seen other customers doing exercises under water.

She said she didn't want him to complain about being disturbed as she had seen other customers unhappy about that previously.

Coroner Matenga asked Kaur questions on behalf of Miklus' daughter, who lived overseas and was not present at the inquest, including why no one pulled Miklus out of the pool when they noticed he was face down in the water.

Kaur said it was common to see people still under the water.

Polynesian Spa health and safety manager Carol Mio, who helped Tibus do CPR on Miklus, also confirmed customers did tai chi and yoga poses in still positions while in the pools.

Toomaru, who was present at the inquest, said when she was first brought to her husband after he was pronounced dead, she asked Mio "what happened?", to which she said Mio told her words along the lines of "there was a problem with the shifting", which she took to mean with the changeover in staff's shifts.

However, Mio said she recalled saying sorry to Miklus' partner but didn't remember saying there was a problem as at that point she had no idea what had happened.

Mio confirmed Polynesian Spa had reduced the temperature of the pool from 42C to 41C since Miklus' death and had employed an additional lifeguard to ensure there were now three monitoring the complex instead of two.

Pathologist Dr Tim Sutton said Miklus had died from drowning.

He said there were no other medical conditions or injuries indicating he had suffered a medical event before drowning.

Dr Sutton said it was his opinion Miklus had fainted in the hot water and drowned.

He said there was also no hydrogen sulphide poisoning present in Miklus' body, as there had been in other hot pool deaths in Rotorua in the past.

"I don't think this is a factor in this case."

Dr Sutton said people could die from heat exhaustion, especially in water as hot as 42C.

"An immersed body in 42C can potentially kill a person."

More witnesses are being called this afternoon.