U.S. jazz singer Al Jarreau was in a critical condition in hospital in France on Friday (July 23) after collapsing on stage the previous evening, hospital sources said.

The 70-year-old singer collapsed during a concert in Barcelonnette in the southeast of France, and was suffering from respiratory problems.

"He was rushed to hospital... his condition is critical. He's in intensive care," said Maurice Marchetti, deputy head of the hospital at Gap.

"He is still conscious but slightly drowsy because of the medication and the breathing apparatus."

A seven-times Grammy award winner, Jarreau is the author of hits such as "Boogie Down" and "Roof Garden."