Filming of the launch show for the next season of Big Brother Australia has reportedly been delayed due to a fire alert.

After an absence of almost six years from Aussie screens, the show was revived by Network Seven earlier this year with a new format that saw the entire series pre-recorded and the public voting aspect removed until the final episode.

Despite initial skepticism from fans, the revamped format proved to be a hit and Seven was quick to order a new season for 2021.

According to TV Tonight, the new season had been due to begin filming on Saturday night but the show's production staff and host Sonia Kruger were evacuated from the compound at the 11th hour following a fire alert in Sydney.

A spokesperson for Endemol Shine Australia confirmed: "Due to the impact of a prescribed hazard reduction burn at North Head, the Big Brother crew on site were safely evacuated.

"Filming is yet to commence and production will resume when it is safe to do so."

The new season is expected to air on Seven early next year.