'Cry Me A River' superstar Justin Timberlake has come under fire from a golf tournament organiser after failing to get involved with a cause when it wasn't being filmed or publicised.

The singer and actor teamed up with Shriners Hospitals for Children several years ago to host a celebrity golf tournament and while he was initially praised for his participation, tournament chairman Raoul Frevel has now slammed his 'off camera behaviour' as uncharitable. 

Speaking to the Las Vegas Review, Frevel said: "We're a world-class organisation. At the time we got involved with golf, we were told by the Tour we needed a big name, and that's how our relationship with Justin came about."

"Justin's a wonderful person. But we tried everything we could to get him more involved with our kids and the hospitals. But it seemed that when the TV cameras weren't on, he disappeared."