Aston Merrygold, Marvin Humes, Oritsé Williams and Jonathan "JB" Gill have recently been recording with the controversial R&B star in the US, The Sun claims.
A source told the newspaper: "JLS have been working in the studio with Chris. Aston was really excited about it and has told pals back in the UK. He was quite starstruck.
"They have been writing and recording together and delivered some great stuff for the second album."
The news comes after a Los Angeles judge yesterday praised Brown for making good progress since his sentence for assaulting ex-girlfriend Rihanna.
JLS's second album is expected to be released later this year, while their new single 'The Club Is Alive' is due to get its first radio airing on Monday.