Lionel Richie discovered he wanted to adopt Nicole Richie at a Prince concert.

Lionel Richie and Nicole Richie

Lionel Richie and Nicole Richie

The 'All Night Long' hitmaker has revealed he knew he wanted to father the 34-year-old fashion designer when he saw her playing the tambourine on stage with the late 'Purple Rain' hitmaker, when she was just two years old.

He shared: "The discovery was not the show for Prince. "The discovery was: there's a two year old on stage with Prince playing a tambourine."

At the time, the 66-year-old musician knew Nicole's real parents, as one of them was in his band the Commodores and he had heard their "family situation was falling apart" so he offered to help out.

Speaking in an episode of The Huffington Post's series 'Talk To Me', in which Nicole interviewed her adoptive father, he said: "I think we decided that ... what we'll do to kind of give you some stability was we'll be like legal guardians, but nothing more."

Lionel and his former wife and childhood sweetheart Brenda Harvey informally adopted Nicole - whose name was Nicole Camille Escovedo - in 1983 and officially took legal guardianship of her when she turned nine in 1990.

At the time Lionel - who also has 17-year-old daughter Sofia and son Miles, 22, with his ex-wife Diana Alexander Richie - was at the height of his career and was constantly away on tour, but always promised Nicole he was never going to abandon her.

He recalled: "I remember you had abandonment issues for obvious reasons. You'd been handed around to every relative in the family. I remember what I said to you. I said, 'I'm never, ever going to leave you.'"

Lionel credits Nicole for "softening" his heart and gushed that he fell "in love" with something that wasn't music.

During the interview he told Nicole:"I think you...changed my life a great deal in terms of softening my heart, because everything up to that point was about songwriting and the business and touring.

"All of a sudden I found something that I could actually fall in love with that was never going to leave me. How about that?"