The television and sporting worlds are mourning the death of Nine's former NRL boss Matt Callander.

The father of four, who helped raise $2 million for cancer research earlier this year through the NRL's Beanie for Brain Cancer round, battled the disease for more than a year. He died on Sunday surrounded by his family.

Callander was the son of media personality and Wide World of Sports racing legend Ken Callander. He worked with Nine for two decades, starting as a producer on the network's Footy Show before facing the other side of the camera as a respected commentator.

"It breaks your heart," Today sports presenter Tim Gilbert told viewers. "A beautiful guy who battled so hard."