Ariana Grande supported her brother Frankie Grande ahead of his return to Broadway.

The 32-year-old pop star offered her sibling some crucial vocal advice before he began his run in Titanique on Broadway, and Frankie has now revealed how his famous sister helped him through a pre-show scare.

Frankie, 43, told E! News: "I asked her vocal advice. I did because I was having trouble because I had a sinus infection."

The actor - who originated the role of Victor Garber during Titanique's Off-Broadway run - had been steaming for up to an hour and a half daily in a bid to clear his congestion, but Ariana quickly stepped in with a more practical solution to his problem.

Frankie - who previously appeared as a contestant on Big Brother in the US - said: "I was steaming, steaming, steaming, steaming, and she was like, 'Bro, you're over-steaming.' And I was like, 'You can do that?'"

Ariana advised her sibling to limit his steaming sessions to just 15 to 30 minutes -- and the results were almost immediate.

Frankie explained: "She was like, 'Chill! Do 30 minutes. Do 15. Stop.' And I got better after that."

Frankie - who made his Broadway debut in Mamma Mia! back in 2006 - also reflected on his role in helping Ariana to find her own feet on stage during the early days of her career.

He said: "It was fun because I kind of raised her. She was raised coming to my Broadway show and then immediately she was on Broadway. In those days I was her mentor for a lot of time."

Despite this, Frankie insists that their relationship has evolved well beyond swapping career tips.

The actor - who performed on Broadway as Franz in the musical Rock of Ages in 2015 - explained: "Now it's just coming to the audience to support each other. Because we know what we're doing at this point."