Billy Connolly has apologised to his fans and assured them he's "not dying, not dead" after making comments in a documentary that his life was "slipping away".

In a cheerful video in which he strums on a banjo while addressing the camera, the Scottish comedian reacted to the outpouring of concern from his fans after he said he's "near the end" in the two-part BBC series Billy Connolly: Made In Scotland.

"Not dying, not dead, not slipping away. Sorry if I depressed you. Maybe I should have phrased it better", he said in the clip which was tweeted by his wife Pamela Stephenson.

The comedian, who was diagnosed with Parkinson's disease in 2013, gave a frank update on his health troubles in the BBC programme.

"My life, it's slipping away and I can feel it and I should", he said.

"I'm 75, I'm near the end. I'm a damn sight nearer the end than I am the beginning. But it doesn't frighten me, it's an adventure and it is quite interesting to see myself slipping away."