SOUTHAMPTON YouTuber Ally Law claims he was locked up in a police cell for "20 hours" after sneaking into the Big Brother house for a second time in a week.

The prankster took to social media to tell followers about his arrest, after he and friend Ryan Taylor were spotted in the reality TV show house, in Hertfordshire.

According to the Mirror, the pair's presence on Friday left the show's housemates begging for help.

They say the intruders got into the garden and started filming the celebs through the glass windows via cameras attached to their heads.

One housemate, Ashley James, shouted: "Oh my god someone is trying to get in," while former Ex on the Beach star, Jess Impiazzi, screamed: “Oh my god help me I’m scared."

Following the incident, Ally Law, who is from Southampton, said on Twitter: "We're free!! me & @ryantaylorbmx just spent 20 hours in a cell."

He also claimed he had been "put on bail".

It is the second time in less than a week that the controversial YouTuber, who has repeatedly been condemned in recent months for hiding in various facilities and centres in Southampton and beyond, is said to have entered the Big Brother house.

According to reports he and a friend were seen in the Big brother compound last weekend, in a move that was then described as the "biggest security breach in the show's history".

In footage posted on Snapchat, housemates on the Channel 5 show can be seen in the background.

Stars including rapper Ginuwine, model Ashley James and Love Island's Jonny Mitchell all appeared in the footage.

In the past, the self-style 'urban explorer' has filmed himself in the city's IKEA store, the Quays Swimming and Driving Complex and at St Mary's Stadium.

Earlier this year, Chelsea Football Club gained a High Court order against the YouTuber, banning him from entering the club's stadium and training ground, without permission.