Bangkok: Thailand`s King Bhumibol Adulyadej will return to a Bangkok hospital for the first time since leaving it a year ago, the palace said in an announcement on Wednesday.
The 86-year-old king would undergo a medical checkup, the Office of His Majesty`s Principal Private Secretary said in a statement. It gave no further details on his health or the length of his stay in hospital.
King Bhumibol, who is the world`s longest-reigning monarch, and its wealthiest, left hospital in August 2013 after he was admitted in 2009 for a lung infection.
The king spent four years living in a special suite at the hospital where he was treated for a range of illnesses.
He has rarely been seen in public since leaving the hospital and lives at the Klai Kangwon Palace - which translates as "Far from Worries Palace" - in the seaside town of Hua Hin, south of Bangkok.
The king is a constitutional monarch who is seen as above the political fray and stayed silent through months of upheaval between supporters of the royalist establishment and a government loyal to former premier Thaksin Shinawatra, run by his sister, Yingluck.
Six months of at times violent anti-government protests came to a head when the army seized power in a bloodless coup on May 22, saying it had to take over to restore stability.
Pro-establishment royalist groups have accused the self-exiled former telecoms tycoon Thaksin of being disloyal to the king. Thaksin denies that.
Thailand has harsh laws designed to protect the monarchy.
Those found guilty of insulting the royal family can serve up to 15 years in prison for each offence.