Martin said he has been working in the studio on new material for Rihanna, reported Billboard magazine.
"I don't think she even asked, I just said, 'please can I try something?'" he said.
It is still unclear whether any of Martin's song ideas will appear on Rihanna's next musical project.
"She has so many amazing people writing for her. It is like trying to win 'American Idol', getting a song on Rihanna's album. It is hard. Everybody wants to write songs for her," he added.