Dreamworld boss Craig Davidson has announced the theme park will refund all pre-purchased tickets valid over the period it remains closed.

In a statement, Davidson said nobody will be left out of pocket as the park and authorities investigate the cause of a ride malfunction which killed four people on Tuesday.

Pre-purchased 1, 3, 7, and 21 day tickets with validity remaining will be fully refunded, and season-pass holders may either extend their pass by the duration of the park’s closure, or receive a refund on a pro-rata basis.

Davidson also outlined the operating procedure for Dreamworld employees, saying staff will be invited to return to work from next week on a totally voluntary basis.

Although the park will remain totally closed to the public until after the victims’ funeral services, and no attractions will operate until they undergo exhaustive safety audits, Davidson said gardening, groundskeeping, and animal care duties will go ahead.

In addition to the upcoming memorial day held in conjunction with the Australian Red Cross, Davidson announced a fund supporting the families and friends of victims Kate Goodchild, Luke Dorsett, Roozbeh Araghi and Cindy Low. Donations can be made here.

The statement comes after last night’s candlelit vigil, which Davidson attended.

A photo posted by Gem (@gemma_elly93) on Oct 28, 2016 at 2:35am PDT

Source: Supplied.

Photo: Glenn Hunt / Getty.