The pair were discussing Oliver's mission to improve school meals

"Do you think we should put something in the water supply, stop some people having children in the future?" the presenter asked chef Jamie Oliver.

But the remark, on BBC One's Friday Night With Jonathan Ross programme, was "not out of character", the BBC said.

Ross was "well-known for his irreverent approach", a spokesman added.

Meals mission

After the star made the comment, Oliver asked: "What, you mean like lead?"

A member of the audience then shouted "Oi!", prompting Ross to point at the crowd.

"There's one," he said. "We could have stopped that happening. See what I'm saying?"

Oliver appeared on the show to talk about his mission to improve the meals served to children at schools around the UK.

The pair had been discussing a recent case in Rotherham, South Yorkshire, where parents passed fish and chips to their children through the school's railings, as a protest against the introduction of healthier menus.