Senate President Scott Ryan has launched an investigation into a physical altercation between former United Australia Party leader Brian Burston and Pauline Hanson’s chief of staff outside Parliament House on Wednesday.

The altercation follows recent events in which Hanson accused Burston of sexual assault, to which he responded that she made sexual advances to him instead.

Senator Ryan says the matter will be regarded with grave importance and urgency.

If you have been affected by sexual assault, there are services to help. Contact 1800RESPECT or visit 1800Respect.org.au.