Singer Bryan Ferry pulled out of a public appearance on Tuesday night after becoming unwell, his publicist has confirmed.
The 65-year-old was admitted to hospital for tests "as a precautionary measure, having felt unwell recently," his spokesman said.
The Washington-born singer had been scheduled to appear at an Olympics 2012 event at the O2 Arena.
The singer later left hospital after a 24-hour stay for routine tests.
He is expected to embark upon a solo tour later this month, his publicist added.
Last month, the star completed a world tour with his former band Roxy Music.
The band's hits include Virginia Plain, Love Is The Drug, Angel Eyes and a cover of John Lennon's Jealous Guy.