When Polish composer Frederic Chopin died in 1849 he seemed to have suffered a classic Romantic death from tuberculosis. But doubts soon arose about the diagnosis, and a scientific examination of the heart earlier this year, while at first appearing to confirm the TB theory, left the mystery unresolved.

It was the dead of night when a secret ceremony took place at a church in the Polish capital, Warsaw, in April this year. A crystal jar, encased in one of the church's pillars, was removed and its contents examined solemnly by genetic and forensic scientists.

"The spirit of this night was very sublime," forensic scientist Tadeusz Dobosz told the Associated Press news agency.