Canada’s newly appointed top military commander has suddenly voluntarily resigned amid a military police investigation.

Defence Minister Harjit Sajjan is not revealing the nature of the allegations against Chief of Defence Staff Admiral Art McDonald.

They reportedly date back to 2010 and involves McDonald, then a naval captain, and a junior female officer aboard HMCS Montreal during a party where there was alcohol.

The news comes just over a month after McDonald took over from General Jonathan Vance, who’s also under investigation following accusations of inappropriate behaviour.

Vance has denied any wrongdoing while McDonald has not commented.

A former naval reservist, who founded a group for survivors of military sexual misconduct, says the allegations against both men underscore the need for external oversight of the military.

Bloc Quebecois Leader Yves-Francois Blanchet says the reputation of the military is at stake and that the government must allow for a thorough investigation.

Lawyer and retired colonel Michel Drapeau says the government should appoint an independent inspector general to oversee the military and, in the absence of that, convene a board of inquiry to investigate the allegations against McDonald and Vance.