The estranged son of Thailand’s King Maha Vajiralongkorn has visited a centre for underprivileged children in Bangkok following a surprise return to the country after 27 years of living abroad.

Vacharaesorn Vivacharawongse’s return was first revealed in a video posted online on Sunday showing him in the arrival area of Bangkok’s Suvarnabhumi International Airport being greeted by well-wishers.

His return came at a sensitive time for the Thai royal family, with the eldest daughter of the king in a coma since December.

The 42-year-old, who works at a law firm in New York, is the second son of King Vajiralongkorn with his second wife Sujarinee Vivacharawongse, a former actress.

The then-crown prince divorced Ms Sujarinee who was accused of adultery in public in 1996. Ms Sujarinee and her children later moved abroad.

The youngest daughter was taken back by the royal family and was given the title Princess Sirivannavari Nariratana but the four sons remain estranged and do not have any formal royal titles.

The Palace has not commented on his visit.

Mr Vacharaesorn went to the Foundation for Slum Child Care and donated money to support their work, according to the foundation’s Facebook post, saying he “greeted the children thoughtfully and took great interest in the foundation’s work of helping underprivileged children and families”.

Photos posted showed Mr Vacharaesorn embracing children and talking to them.

A day after his arrival, Mr Vacharaesorn was seen in videos visiting several religious sites in Bangkok, including the Temple of the Emerald Buddha which is in the Grand Palace’s ground.

He posted on his Facebook account a photo of himself on an auto-rickshaw at night with the caption “Bangkok Tuk-Tuk”.

King Vajiralongkorn, 71, has married four times and has seven children but he has not named an official heir.

His fourth marriage to Queen Suthida was announced just days before his coronation in 2019. The king took the crown following the death of his father King Bhumibol Adulyadej in 2016.

In December, the palace said that Princess Bajrakitiyabha Mahidol, 44, collapsed due to heart arrhythmia, which it later said was from a mycoplasma infection.

She has been unconscious and remained on life support since, according to the palace’s latest statement on her condition in January.