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

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 Channel Seven.

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

A metal ladder is then shown being lowered from the corridor’s ceiling, as Big Brother continues: ‘What happens in my attic will turn the game on its head.’

The dimly lit space upstairs appears to have bunk beds and storage items stacked high and covered in dust.

Eerie: A trailer shows a metal ladder being lowered from the corridor’s ceiling. The room itself is a dimly lit space with bunk beds and storage items stacked high and covered in dust

The housemates look shocked in the trailer and run around the house frantically.

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

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

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

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

The attic space is the second secret room to be unveiled so far this season.

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

Big Brother Australia continues Tuesday at 7.30pm on Seven

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