United Kingdom, June 27 -- Joan Rivers' daughter Melissa has revealed the "true and official story" about why her mum changed her name.

The comedienne and presenter, who died in 2014 aged 81, was born Joan Alexandra Molinsky, but became famous as Joan Rivers.

Melissa told her followers she's questioned regularly about the reasons behind Joan's moniker choice, so decided to take to her Instagram page to set the record straight.

"A lot of people ask me where the name Rivers comes from. And I'm going to tell you the true and official story," she began.

Despite Melissa's confident start to the video, she went on to admit she's "not really sure".

She said that Joan told her "it was the last name of one of her managers, or that one of her ...