A British rescuer who helped save Thai schoolboys from a flooded cave in 2018 has returned home after suffering pneumonia.

Vernon Harry Unsworth, 70, was discharged on October 7 after two weeks of treatment under royal patronage at the Mae Sai Hospital in Chiang Rai province.

The hero cave diver - who once sued Elon Musk for calling him a 'pedo guy' - was rushed to the facility on September 22 when he began coughing violently and struggling to breathe.

Hospital director Ratthakarn Paramee said Vernon's condition has improved and he was allowed to continue treatment at home, where an electric oxygen machine had been installed.

He added: 'Doctors will continue checking his symptoms. Pneumonia can sometimes occur in the elderly.'

Attapol Charoenchansa, Director-General of the Department of National Parks, Wildlife and Plant Conservation, visited the Brit on Wednesday on behalf of the Minister of Natural Resources and Environment.

Vernon thanked the officials and promised to help survey caves in Thailand when he is healthy again.

Vernon is a British cave explorer who lives in Chiang Rai and played a crucial role in the dramatic 2018 Tham Luang cave rescue in which 12 boys and their coach were saved after monsoon flash floods left them trapped.

He used his extensive knowledge of the cave system to help the expert international rescue team, including Navy SEALS and divers, safely extract the 13 people, who were all miraculously brought out alive after the two-week effort.

However, he was entangled in a legal dispute with eccentric and divisive Tesla founder Elon Musk, who took offense when the caver described his proposed rescue mini-submarine as a ‘PR stunt' that he could 'shove where the sun doesn't shine'.

Musk made allegedly defamatory tweets, calling Unsworth a ‘pedo guy,' which he later claimed was a common phrase in South Africa, where he grew up.

Vernon sued Musk for defamation, calling Musk a 'billionaire bully' and claiming the comments had damaged his reputation. He sought 190 million USD in compensation, but a US court ruled in favour of Musk.