LONDON -- One of the ballet world's brightest but most volatile stars has vanished, again.
Sergei Polunin had been due to star in a dance piece based on Billy Hayes' prison memoir Midnight Express opening next week in London.
But director Peter Schaufuss says the 23-year-old dancer did not show up for rehearsals on Wednesday.
The Ukrainian became the youngest-ever male principal dancer at Britain's Royal Ballet when he was 19, but walked out of the company last year, saying he was giving up dance.
He later said he had quit because he was under too much pressure.
Polunin has since returned to performing with Moscow's Stanislavsky Ballet and has made guest appearances with the Royal Ballet.
Polunin's whereabouts could not immediately be determined Friday.
-- The Associated Press