Rock legend Mick Jagger is set to be a father again at the age of 72 after it was revealed his 29-year-old girlfriend is pregnant with his child.

Melanie Hamrick, a professional ballerina, who has been dating Jagger since 2014, is three months pregnant.

According to The Sun, the couple were "surprised and happy" after finding out they were expecting.

"This is great news. It will be Mick's eighth child and nothing fazes him. He's been incredibly supportive," the paper quoted a source close to Ms Hamrick as saying.

The new addition will be Jagger's eighth child.

The news comes little more than a month after fellow Rolling Stone Ronnie Wood, 68, welcomed twins.

Jagger's eldest daughter is 45-year-old Karis Hunt Jagger, who he had with 1960s icon Marsha Hunt.

His daughter Jade Jagger is from his marriage to Bianca Jagger.

The rockstar had four children with Jerry Hall, and has a 17-year-old son, Lucas, from a relationship with with Brazilian TV presenter Luciana Gimenez.