Glen Hansard and Marketa Irglova reunite to see Once the Musical on Broadway

The 2006 low budget indie romance filmed in Dublin brought the pair together, and their affair continued off screen, with the couple becoming the toast of Hollywood when they attended the 2008 Oscars and performed the theme tune from the movie that also won them an Oscar.

The musicians continued their romance and formed The Swell Season, but over a year later Hansard confirmed their split.

But it was a love story without a happy ending, as in January 2009, after three years touring with group The Swell Season, the couple announced they had split. "We broke up because neither of us were really enjoying it," Hansard said later.

24-year-old Irglova last summer announced on Twitter that she had married a music engineer Tim Iseler. Her message was immediately shared on Twitter by 42-year-old Hansard who simply said "Congratulations Marketa!!! Happy marriage!!!"

The musical of the movie opened off Broadway in December to generally favourable reviews.

Meanwhile, a revealing documentary following the couple from the moment they won the Best Song Oscar for Falling Slowly, to their split is receiving acclaim at film festivals around the globe.

The intimate portrait of Hansard and the Czech-born Irglova has received a rave review in the Los Angeles Times.

The newspaper describes the black and white documentary entitled The Swell Season, after the group they formed following Once: "as an incisive cut at fame's effect on the real-life music and romance of Hansard and Irglova".

Filmmakers Nick August-Perna, Chris Dapkins and Carlo Mirabella-Davis (who once taught Hansard filmmaking in New York and became a friend) were given almost unlimited access to the couple for nearly three years.