It was reported before this year's series started that Tulisa was worried about what her cousin may say about her inside the house.
“Tulisa is scared Dappy may forget the cameras are rolling,” a source told Star magazine last week. “Their pasts are pretty colourful and Tulisa’s public image has already taken a pounding."
But speaking before he entered the house, Dappy revealed that he had agreed with Tulisa not to mention her name or respond to any questions about her.
The N-Dubz star explained to the Daily Star Sunday newspaper: Tulisa asked me not to talk about her on the show at all. If I’m asked about her by other housemates I won’t answer.
“I’m protective of her.”
It's been a bad twelve months for Tulisa, who was involved in a sex tape scandal, booted from the X Factor and most recently taken to court on drugs charges.
Dappy claimed that the tabloids had been trying to "ruin" his cousin, saying: “They’ve tried to ruin her so much. Tulisa’s upbringing was really crazy. She had a difficult time.
“When you grow up on an estate from a young age and you are broke, it’s tough.
“Tulisa had a very hard life. So did I. That’s why we’re so close.”
Celebrity Big Brother 2014 airs nightly on Channel 5.