The exiled son of Thailand's notorious 'crop top king' returned to the country on Sunday night amid questions over the heir and chaos surrounding the recent sham election.

Vacharaesorn Vivacharawongse, 42, and his three brothers were banished when King Rama X, then crown prince Maha Vajiralongkorn, accused their mother Sujarinee Vivacharawongse of adultery in 1996.

However, the king's only other recognised son Prince Dipangkorn suffers from learning difficulties and his sister Princess Bajrakitiyabha - who many believed would be regent as next-in-line - is being kept alive artificially in hospital following a collapse in December last year.

Vacharaesorn, a lawyer in New York, arrived at the Suvarnabhumi International Airport (BKK) on August 6. He had previously criticised the military junta's sham election held on May 14 which saw the winner Pita Limjaroenrat banned from politics and threatened with jail.

King Maha Vajiralongkorn is best known for keeping a harem of sex soldiers in a hotel in Bavaria during lockdown and walking around a shopping mall in a crop top while plastered with fake tattoos.