The 58-year-old was one of the biggest TV stars of the 1970s. His BBC shows Look - Mike Yarwood and Mike Yarwood in Person were prime time favourites, making him as much a household name as those he impersonated.

Famous for his impressions of Prime Ministers Harold Wilson and Ted Heath, Yarwood struggled to maintain his creative momentum after the election of Margaret Thatcher.

Having regularly attracted audiences of more than 20 million, Yarwood found the decline of his career in the 1980s difficult to adjust to.

Although the troubled star is free from his former alcohol addiction, he has suffered a relapse of the mental health problems which plagued him after his showbiz career slumped.

"He has suffered from depression and panic attacks before and I am afraid to say the problems have resurfaced," said his agent, Pat Lakesmith.

The comedian entered the clinic last week and will stay as long as is needed, according to Lakesmith.

"Hopefully he will overcome these difficulties with professional help."