PERTH, Scotland - The World Curling Federation has extended a ban on controversial broom heads to all events for the 2015-16 season.

Olympic gold medallists Brad Jacobs, Brad Gushue, Jennifer Jones and former world champion Glenn Howard were among 50 Canadian and international teams who signed a statement released Oct. 14, saying their teams will not sweep with broom heads that have "directional fabric.''

Coarse material on the broom heads creates a sandpaper effect on the ice and with it, sweepers have been able to manipulate the rock's trajectory in ways they never could before.

Fearing that throwing accuracy and athleticism would be diminished, the curlers said they want to protect "the integrity of the game'' in refusing to use the brush heads.

The WCF has outlawed both fabric that has been "textured, sealed or modified from its original woven form" and hardening or stiffening inserts in the brush head, according to a statement released Wednesday.

"This includes fabric which has a woven appearance, but which has had a PVC (or similar chemical) waterproofing treatment applied over the woven surface, effectively sealing the outer side of the fabric in contact with the ice."

Brush heads constructed of fibres that had waterproofing applied before woven into material will be allowed, however. Only sweeping equipment sold retail to the public as of Nov. 17, 2015, and not modified will be allowed on the ice.

"The primary objective of this moratorium is to ensure a fair and level playing field and to respect the principle that any technological advancements or innovations have a positive impact on the sport and its traditions, and that athletic performance and mental skill are the dominant elements for success," the WCF said in a statement.

The organization instituted an interim ban on the brooms at last week's Pacific-Asia Championships in Kazakhstan. The moratorium now includes all WCF events. The European championship starts Thursday in Esbjerg, Denmark.

Curling Canada didn't immediately implement the same rules.

"We will have to review and determine to what degree we will adopt," high-performance director Gerry Peckham said in an e-mail. "We have not had the time to do so."