The youngest son of the Shah of Iran has killed himself after a long battle with depression - following his model sister who also took her own life.
Tormented by his sister’s death and the upheaval in his native country, Alireza Pahlavi, 44, shot himself in the head at his home in Boston, where he was studying at Harvard University.
His brother, former crown price Reza Pahlavi, said the family was in ‘great sorrow’ over the tragedy.
A family statement confirmed: ‘It is with immense grief that we would like to inform our compatriots of the passing away of Prince Alireza Pahlavi.
‘Like millions of young Iranians, he too was deeply disturbed by all the ills fallen upon his beloved homeland, as well as carrying the burden of losing a father and a sister in his young life.
‘Although he struggled for years to overcome his sorrow, he finally succumbed.’
The Shah, Mohammad Reza Shah Pahlavi, died in exile in Egypt in 1980 - just a year after being ousted in Iran’s Islamic revolution.
Princeton-educated Mr Pahlavi, who was studying for his doctorate in philosophy and ancient Iranian studies at Harvard, never recovered from the loss of his younger sister, Leila.
A one-time model for Italian designer Valentino, she too suffered from bouts of deep depression and also battled anorexia and bulimia.
She was found dead in her room at the Leonard Hotel in London in 2001 when she was 31, after taking a cocktail of cocaine and more than five times the lethal dose of quinalbarbitone - a prescription drug used to treat chronic insomnia.
Her brother, who lived between Boston and Paris, is said to have killed himself in the early hours of the morning.
The family learned of his death at 2.30am, according to a spokesman.
Born in Tehran in 1966, Mr Pahlavi attended schools in Iran before fleeing with his family to the United States in 1979.
After Princeton, he went on to get a master’s degree from Columbia University in New York.
The youngest surviving of the Shah’s five children, he never married and shunned the spotlight.
While his older brother spoke out against the violent crackdown in Iran following the disputed elections last year, he kept his own counsel.
A statement released by the crown prince's office said: ‘Prince Ali Reza was intelligent, sensitive, loyal, and dedicated to Iranian civilisation, as well as to his family and friends.
'His counsel, wisdom and sense of humour will be profoundly missed and always cherished.’
Boston police confirmed that no foul play was suspected in the death.
His sister’s suicide followed a similar struggle with depression and crippling low esteem.
After her death, her mother Farah wrote on a remembrance website: ‘Exiled at the age of nine, she never surmounted the death of her father, His Majesty Mohammad Reza Shah Pahlavi, to whom she was particularly close.
‘She was never able to forget the injustice and the dramatic conditions of our departure and the erring which was to follow.
'She could not stand living far from Iran and shared wholeheartedly the suffering of her countrymen.’
Mr Pahlavi is survived by his mother, his older brother, his sister Farahnaz and his half-sister Shahnaz.