Sir Elton John made an outburst at the recent Q Awards

The 57-year-old appeared on the show, hosted by Chris Moyles, and swore just after 9am, using the f-word before joking: "I'm not live on air, am I?"

Moyles then told his guest: "Yes, we're live. I apologise to the young boys and girls. But it is Elton John."

A Radio 1 spokeswoman said: "Elton was warned several times about swearing. We apologise if we offended anybody."

After the initial exchange, Sir Elton listed a string of swear words and asked if they were permissible on air.

"I'm sorry, I have this weird syndrome approaching 10am," he added.

After apologising again, Moyles said: "Thanks everyone, you're listening to my last show on Radio 1."

Sir Elton has built up a reputation for unpredictable outbursts in public over recent months.

At the recent Q magazine awards, Sir Elton used strong language to lay into Madonna after she was voted best live act.

He also lashed out at press photographers in Taiwan, calling them "rude, vile pigs".