The comedian wrote the bluegrass musical with his frequent collaborator Edie Brickell, but box office sales aren't as high as the duo had hoped.

For the week ending 29 May (16), the show took in just over $443,000 (£307,000) - over $150,000 (£104,000) less than the weekly production costs, according to the New York Post.

And, despite landing five Tony Award nominations, including Best Musical, the show hasn't seen a significant rise in sales. As a result, Martin and Brickell, along with their fellow producers, are helping to keep the show open at least until the 12 June (16) prizegiving, where the cast will perform a number from the show and hopefully boost sales.

The New York Post reports Martin, Brickell, and her husband Paul Simon have poured in more than $1 million of their personal funds to help Bright Star keep shining.

While the stars confirmed the extra investments, a representative for Martin and Brickell did not disclose exactly how much they put towards the show.

A statement to the New York Post reads: "We love our show and the family that has been created at the Cort Theatre. We are lucky to have been in the position to help it and should also acknowledge the support of the 12 other backers who have also invested additional money since. We are thrilled for the accolades Bright Star has received, including the Outer Critics Circle Award for best musical and five Tony nominations. We hope the momentum has a lasting impact."

Bright Star began Broadway previews in February (16). Martin is up for Best Book of a Musical at the Tonys, as well as Best Original Score with Brickell.