On Day 43, a sniffer dog found a suspect package near to the house and directly near the stage where Davina McCall interviewed evicted housemates. The package was believed to contain a bomb and was found during a routine security check.

Just before 20:00, housemate Scott was informed in the Diary Room by Big Brother that all housemates were to go to the boys bedroom and remain there until further notice. Around 20:45, Hertfordshire Constabulary police force advised that all housemates were to be evacuated. Production staff and a camera crew entered the house, made them aware of the security alert and evacuated them. They were taken to a secure area on the perimeter of the studio complex, with high levels of security accompanying them.

At 21:35, Marcus Bentley informed the viewers that the Big Brother gallery, where the production crew monitored the house, also had to be evacuated, all filming was required to stop and as a result, cameras were turned off and all filming of the housemates in the secure area wasn't permitted, however they were still required to follow the rules of the show.

A 100metre cordon was put into force around the house by police where the press and audience were required to wait for their safety. Bomb disposal police carried out a controlled explosion of the suspect package around 22:00 and turned out to be a false alarm. The all clear was given by police around 00:00. Just before 01:00 on Day 44, housemates were permitted by police to reenter the house.

Two live shows at 20:30 and 22:00, where a housemate was due to be evicted, were cancelled by Channel 4 at short notice and instead, an episode of Friends was broadcast in its place. The eviction went ahead on Day 44 without a studio audience.