Musician Prachathip Musikapong, son of red-shirt leader Veerakan Musikapong, fell to his death from the ninth floor of a condominium in Bangkok late on Wednesday.
Prachathip: Fell five floors
His body was found on a fourth-floor balcony about 11.30pm. A failed love life was believed to have led to the apparent suicide.
Police said Mr Veerakan, a key figure of the United Front for Democracy against Dictatorship, had lost one of his four sons at the Thong Lor condo.
Mr Veerakan said he believed his son jumped to his death because a suicide note was found that described problems regarding his girlfriend.
Mr Veerakan said funeral services would be held at Wat That Thong in Bangkok.
Bangkok police chief Sriwara Rangsipramnakul said police considered the death as a suicide as relatives confirmed the handwriting on the note was Prachathip's.