Farrell performed as scheduled in St. Petersburg on Wednesday night, but complained of breathing problems before and after his show, said the agent, John Seine. He had been due to fly to Rome Thursday for a television show.
Farrell, who lived in Amsterdam, was more a dancer and showman than singer when he headlined Boney M in the 1970s. The group, based in Germany, broke into the charts with "Daddy Cool" in 1978. That year their version of "By the Rivers of Babylon" sold nearly 2 million records in Britain alone, keeping it No. 1 for five weeks.
Alphonso "Bobby" Farrell left his home on the Caribbean island of Aruba at 15 to work as a sailor, then drifted to Norway and Germany to pursue a career as a DJ, according to his official biography.
He was chosen in 1974 to front the Caribbean group Boney M, put together by German singer and songwriter Frank Farian, who did much of the recorded singing. Boney M had 38 top-10 hits, including 15 number ones in Germany. They included "Brown Girl in the Ring" and "Mary's Boychild."
In 1978 Boney M was the first Western music group invited by a Soviet leader, Leonid Brezhnev, to perform in the Soviet Union. A Soviet military plane flew the performers from London to Moscow, where they sang for an audience of 2,700 Russians in Red Square.
The original group of Farrell and three women broke up in 1986 and Farrell continued on his own or with various female back-up singers, maintaining his flamboyant style and glittering costumes. In recent years he toured under the name Bobby Farrell's Boney M, melding disco and Calypso music.
Seine said the cause of death was not known, but Farrell had suffered health problems off-and-on for 10 years. He said he was found dead by hotel staff after he failed to respond to a wake-up call.