Strict anti-protest laws may have encouraged mining conference to move from Melbourne to Sydney

Legal observers also say, separately, that law enforcement agencies in New South Wales, Victoria, Queensland and the ACT have been pre-emptively visiting the homes of climate activists in an effort to intimidate protesters ahead of the conference next week.

The International Mining and Resources Conference (Imarc) is being held from 2 November in Sydney and has faced pressure from activists under the banner Blockade Imarc.

Not all the mining companies connected with the event are involved in fossil fuel extraction, but the World Coal Association is a host partner. Speakers include representatives from the Saudi Arabian and Sudanese governments.

The three-day conference includes exhibitions, networking events and presentations on issues involving mining; the opening session is titled Promoting Opportunities, Minimising Disruptions and Building Resilience.

South Australia has a slot alongside Chile for a session showcasing opportunities for exploration and project development. SA mining and energy minister Tom Koutsantonis is scheduled to speak.

A notice on the conference website warned attendees of potential disruptions and advised them not to wear a name badge outside the conference or engage with protesters.

Brad Homewood, 49, from Williamstown, Victoria was among the climate activists in the state to receive a visit from police.