UPDATED 8.11am: Investigations will begin this morning into a devastating fire at a famous North Canterbury rugby club.

Hurunui's Glenmark club has been almost completely destroyed by a blaze that ripped through just after midnight.

Club secretary Hamish Black said it's a huge blow.

"That sort of stuff you can't buy back unfortunately."

"Lots of team photos, framed jerseys and other memorabilia, that was all on the walls so it was like a museum for the Glenmark club."

Crews were on the scene for almost four hours.

Rugby greats like Todd Blackadder, Robbie Deans and Alex Wyllie have belonged to the club over the years.

Fire communications shift manager Riwai Grace said they hope to work out the cause of the blaze today

"Seriously seriously damaged, haven't been able to determine the cause so the fire investigator along with police will be doing an investigation."

He added that "it's quite a well known rugby club, and I'm sure there's a lot of devastated people."