Big Brother twist: Housemates face ‘the most SHOCKING surprise of all’

Big Brother twist: Housemates face ‘the most SHOCKING surprise of all’ as a secret room is revealed to stars

It’s ‘Surprise Week’ in the Big Brother Australia house.

And on Tuesday, the housemates will be introduced to an epic twist.

Host Sonia Kruger has promised ‘the most shocking surprise of all’ in a sneak peek trailer released by Seven.

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Big Brother SHOCK twist: Housemates face ‘the biggest surprise of all’ on Tuesday as a secret room is revealed to stars. Pictured: Marley Biyendolo

‘My house has surprises around every corner, but did you ever think to look up?’ the mysterious Big Brother voice says in the clip.

Footage is then shown of a secret metal ladder lowering down from the corridor’s ceiling, as he continues: ‘what happens in my attic will turn the game on its head.’

The creepy dimly-lit space appeared to have bunk beds and storage items stacked high covered in dust.

Eerie: The creepy dimly-lit space appeared to have bunk beds and storage items stacked high covered in dust

Eerie: The creepy dimly-lit space appeared to have bunk beds and storage items stacked high covered in dust

Shocked housemates are shown in the trailer, as well as a scene of the cast running around frantically.

During Monday’s episode, the housemates were tasked with ‘remaining as cool as a cucumber,’ while they faced a series of surprises.

Confetti canons, scary clowns, spiderwebs and a chihuahua were some of the items used by Big Brother to incite panic, excitement and shock. 

Challenge: During Monday's episode, the housemates were tasked with 'remaining as cool as a cucumber,' while they faced a series of surprises

Challenge: During Monday’s episode, the housemates were tasked with ‘remaining as cool as a cucumber,’ while they faced a series of surprises

MORE secret rooms: During the first week, Daniel Hayes (left) and Nicholas Benton (right) snuck away to an underground boiler room to become exempt from the first eviction

The anticipated attic space is the second secret room to be unveiled for this season.

During the first week, Daniel Hayes and Nicholas Benton snuck away to an underground boiler room for two nights to become exempt from the first nominations and eviction.

Big Brother Australia continues Tuesday at 7.30pm on Seven

Tune in: Big Brother Australia continues Tuesday at 7.30pm on Seven

Tune in: Big Brother Australia continues Tuesday at 7.30pm on Seven