Former Baywatch star Jeremy, 34, has suffered addiction problems in the past and Perez told BB last night that he is concerned the actor is slipping back into his old ways.
Speaking in the Diary Room, US blogger Perez said: "Coming into this house, I was already concerned about one housemate who was rumoured to be coming in. And he has already proven to me to be very concerning, and that's Jeremy.
"The fact that Jeremy is boozing a lot after being super sober, which he expressed to me, and is just coming out of a bad break-up, makes me think that he's not in a very mentally stable place.
"He is a big red flag to me. I mean, there's entertaining and then there's scary - and he is borderline scary."
Earlier in the show, Perez was seen talking to Jeremy about the time he was romantically linked to Lindsay Lohan. Jeremy explained that it was "when he was sober", leading Perez to ask if he is no longer teetotal.
Jeremy replied: "You just watched me drink, like, nine glasses of champagne."
Perez then frankly asked: "Is that not a relapse at all?" Jeremy, however, shot back: "No, nope. It's really not one thing, it's just excessive personality. I don't like to be confined by conditions."
As a child, Jeremy starred as Hobie Buchannon in hit TV series Baywatch. In 2011, the American star appeared in US reality show Celebrity Rehab with Dr Drew after battling an addiction to steroids.
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Copyright: Channel 5