The family of a South African man who assisted in the cave-diving rescue of a group of young Thai football players this week said they were “extremely proud of him”.

Leandro Nicholas Gerardo, 32, who lives in Thailand, gave up his holiday to volunteer in the rescue operation and informed his mother about his plans on Monday.

His brother, Ramiro, said Leandro told his mother on Monday: “Mom, don’t worry, I’m just going to be supplying oxygen and helping with the stretchers.”

Ramiro said his brother was part of a team that was based 2.9km into the cave system and was receiving the stretchers from the Thai Navy Seals who were 4km into the cave where the boys were trapped.

His team assisted with rescuing the last five boys, but Ramiro said despite all the praise heaped on his brother, Leandro insisted that he was no hero.

Ramiro said his brother told him the rescue team had been using around 200 cylinders of oxygen a day and worked under “very difficult conditions”.

Praise for volunteers

He said visibility was near zero and they were “diving blind with jagged rocks” around them. Divers had to squeeze through openings as small as around 40cm in diameter.

“There was little contact until yesterday (Tuesday) when he messaged: ‘Just leaving Chamber 3. All the boys are safe’,” Ramiro said on Wednesday.

“He is stressing that he is no hero and it was a combined effort,” he said of his younger brother.

The rescue team Leandro Nicholas Gerardo was part of. He is in the back row, 6th from the left. (Supplied)

Leandro was not available at the time of writing as it was understood he was on a plane back to Bangkok.

“He (Leandro) was extremely proud to be with the international team of divers and praised the volunteers profusely,” Ramiro said.

While there were many dangers associated with the operation, Ramiro said he had been confident in Leandro’s capabilities.

“I have dived with Leandro before, I can tell you that he is extremely capable and I was not worried for a second,” Ramiro said.

“My mom and dad, who are in Argentina, said they are extremely proud of his sacrifice and his attitude to help others,” he said.

Their sister wrote on Facebook that Leandro was “an absolute legend”.

“He has mentioned that he feels gratitude to his friends and family but there were 20 more divers and he doesn’t deserve credit as it was a team effort,” Ramiro added.

He said Leandro was trained in Durban and was currently working for Mermaid Subsea services in Thailand.

“As soon as he qualified as a dive technician, he started improving his skills and qualifications by working and travelling around the globe. By the age of 25 he was already designing and manufacturing sophisticated equipment for divers,” Ramiro added.