Reinhardt was rumoured to be working on a new reality programme with the hotel heiress, documenting their romance amid reports he has been planning to propose.
A representative for Hilton denied the claims on Monday (22Mar10), insisting the socialite couple had not signed up for such a show - but Reinhardt has now confirmed his own plans with his younger sister.
His agent Greg Weiss tells the New York Post's gossip column Page Six, "Doug is producing the show, which will star his sister and her friends. But he and Paris will also make appearances."
Casey Reinhardt, 23, previously starred in the second season of MTV reality show Laguna Beach: The Real Orange County, while brother Doug appeared on The Hills.
The Simple Life star sparked claims of an impending wedding at the Hearts for Hope benefit in Los Angeles last weekend (06-07Feb10) where she was presented with an award for her charity work.
Accepting her accolade, Hilton, who attended the event with Reinhardt's sister Casey and her beau's mother, told the audience, "I'd like to thank my future sister-in-law Casey..."
But the socialite's mum Kathy Hilton is doubtful of the reports, telling GossipCop.com the rumoured engagement is "news to me", adding that Paris "hasn't mentioned it to me".