Australian Rugby Union boss Bill Pulver has sent condolences after a 25-year-old player died during a rugby match on Sydney's northern beaches.
Lachlan Ward was playing for Warringah Rugby Club on Saturday when he collapsed during the game at Pittwater Rugby Park.
Emergency services performed CPR but he died at the scene, police say, with a report now being prepared for the coroner.
"We are deeply saddened to learn of Lachlan's passing in such tragic circumstances on the rugby field yesterday afternoon," Mr Pulver said in a statement on Sunday.
"Our thoughts and sincere condolences are with Lachlan's family, his teammates, friends, and all at the close-knit Warringah Rugby Club and NSW Rugby Union.
"Outside of Lachlan's family, there were many witnesses to yesterday's events at the ground and those brave players, volunteers, medical and club staff who assisted Lachlan are also in our thoughts today.
"We will work with NSW Rugby Union to support all those affected by this tragedy."
NSW Rugby Union confirmed Ward's death in a statement on Saturday evening.
"The NSWRU would like to extend our deepest sympathy to the players family and to all members of the club," the statement read.
"At this time and out of respect to the family there will be no further comment."
The Warringah Rats Official Supporters Page posted to Facebook advising any remaining games at Rat Park on Saturday had been cancelled.
Randwick Rugby and Norths Rugby clubs were among those to send condolences to the family of the deceased player and the Warringah Rugby Club on social media.
Fans also took to Facebook after news of the death filtered through the club.
"Thoughts are with this beautiful boy and his family, terrible loss," one woman wrote.
"We are so sad to hear this devastating news. Our thoughts are with the family and all the Rats," another wrote.
The man is understood to have been playing for Warringah's fifth grade team.