Any of the players in question who do not participate in the investigation, which will be led by an independent third party, will be banned from all Hockey Canada activities and programs effective immediately, the national governing body said.
"We know we have not done enough to address the actions of some members of the 2018 National Junior Team, or to end the culture of toxic behaviour within our game," Hockey Canada said in an Open Letter to Canadians. "For that we unreservedly apologise."
In April, a woman filed a lawsuit that alleged she was sexually assaulted in a hotel room by eight hockey players following a Hockey Canada golf and gala event in 2018.
Hockey Canada settled the lawsuit in May. The allegations against the unnamed players have not been proved in court.
Last month, the Canadian federal government froze funding to Hockey Canada over its handling of the alleged sexual assault and out-of-court settlement while a number of sponsors have paused their relationship with the organization.
The decision to re-open the investigation was one of a handful of steps unveiled on Thursday as Hockey Canada looks to address the behaviours, on and off the ice, that conflict with what it said Canadians want hockey to be.
Hockey Canada said it will now require all high-performance players, coaches, team staff and volunteers to participate in mandatory sexual violence and consent training.
It will also conduct a governance review of Hockey Canada, create an independent and confidential complaint mechanism and is committed to becoming a full signatory to the Office of the Sport Integrity Commissioner.
In addition, Hockey Canada said it will release an "Action Plan" outlining steps it will take within the organization, and with partners and stakeholders, to advance and improve the culture around the game.
"Changes to policies and procedures can occur with the stroke of a pen. Those changes are meaningless, however, without an equal commitment to addressing the toxic behaviour that exists in many corners of the game," said Hockey Canada.
"We know this change will not occur overnight, but we are committed to learning, and working with our partners to do better."