NEW YORK (AFP) - Celebrity couple Justin Timberlake and Jessica Biel are expecting their first child, Timberlake's former bandmate says.

Joey Fatone, who performed with Timberlake in the boy band 'NSync, confirmed Biel's long-rumored pregnancy in an interview to be released on Wednesday.

"He told me a while ago, and I kept my mouth shut," Fatone told In Touch Weekly.

"Jessica is awesome, and Justin is a kid at heart," he was quoted as telling the magazine.

Timberlake, 33, made his start as a child television star before joining 'NSync.

He has more recently become one of the most popular solo singers and starred in movies including the 2010 Facebook drama The Social Network. Timberlake in 2012 married Biel, 32, who has found success both on television and in film.