A heavily-tattooed glamour model, a former police officer and a woman who runs a "gold-digger" website are among the housemates on this summer's Big Brother - unaware that a professional actor has joined them in the TV house to create mayhem.
Michael Dylan, 29, has told his housemates he is a postman from County Cork in Ireland, but he is really an actor recruited by the programme to "spin a web of secrets and lies".
Last night's show - the first part of the series launch - came as police warned broadcaster Channel 5 over the risks of having a former police officer as a contestant.
Scotland Yard said it had contacted the television station after a newspaper claimed that a detective constable who worked on a high-profile case will be appearing on the show.
The Daily Star - which is owned by the same media mogul who owns Channel 5 - reported that Dan Neal, 33, played a key role on Operation Yewtree, the investigation into Jimmy Savile.
Mr Neal told the paper that he thought his appearance might "cause a stir" within the police, but does not believe it will shame the service.
"I don't see why it would," he said. "It's not like i'm going into some porno industry."
He added that he is "blaming the Government" for his dramatic career change, because of "changes to our pensions".
Scotland Yard said it had made the broadcaster aware of "potential risks" to ongoing police investigations and reminded the company of its "responsibility".
A Scotland Yard spokesman said: "We are aware of reports concerning the proposed media appearance of a former detective constable.
"We have been in contact with Channel 5 and made them fully aware of potential risks and their responsibility to live investigations.
"All officers joining the MPS and leaving the MPS are required to sign the Official Secrets Act."
The former officer is expected to enter the Big Brother house tonight.
Meanwhile, other housemates to go into the house last night included a deaf footballer and identical teenage twins who work in a supermarket .
The launch of the show, hosted by Emma Willis, was given a staggered start with a further selection of hopefuls to be added tonight.
As ever, the show has attracted an array of wannabes. They include nude model and aspiring DJ Sallie Axl, a mum-of-one with a full sleeve tattoo who claims to have slept with 70 women.
Also taking part is Dexter Koh, who claims to have been a highly-paid escort, strip club manager and magician, calling himself a "Jack of all trades" and a "social chameleon".
Jemima Slade owns a dating website, said to have 40,000 clients, which puts women in touch with wealthy men. The 41-year-old single mum says she likes to date toy boys.
Another contestant is Sam Evans, who was born with severe hearing loss and as a result has difficulty with speaking clearly. He has represented national deaf football teams and said he has never had a girlfriend.
Stage musical-loving twins Jack and Joe Glenny are both Conservative Party supporters, have shared a bedroom for many years and said of themselves: "We're funny, we're friendly and we're fat."
Callum Knell, 28, a children's sports coach, who said he is worried that his housemates will be annoyed by his "very good looks", was the next person into the house.
Wolfy Millington, 20, a student who is a practising Shaman and says she connects "with Earth through love and harmony", entered the house barefoot.
She described herself as a "hardcore lesbian fisherwoman" and said: "This is my dream since I was about 12."
Sophie Lawrence, 20, a dental nurse and black belt in karate, also took her place in the house. She said: "I can't stand people that are stuck up and think they're God's gift."
Housemates will this year have to show they have practical skills because their new home includes an allotment area where they will be expected to grow their own food. And they will have to pedal a cycle to generate their own electricity during their stint on the series, this time known as Big Brother: Secrets & Lies, which will last throughout the summer.
Big Brother was launched on Channel 4 in 2000 but moved to Channel 5 in 2011 where it has struggled to match its previous ratings. The audience has dipped to below a million viewers at times.
This series sees Willis taking over presenting duties from former Big Brother contestant Brian Dowling.