Channel 4 has said an external investigation into allegations made by the culture secretary, Nadine Dorries, that a reality TV show she appeared on used paid actors has found no evidence of fakery. The broadcaster asked the producers of the 2010 reality show Tower Block of Commons, in which Dorries was one of a number of MPs who went to live in deprived communities, to investigate the claims she made to the culture select committee in May. The outcome of the investigation, undertaken by Love Productions and overseen by external lawyers, was reviewed by Channel 4, which also conducted its own “internal document searches and review”. “The investigation encompassed contributors who were ordinary members of the public and with whom the secretary of state had significant interaction,” said Channel 4 in a statement on Friday. “It involved speaking with many of those involved in the making of the series, including contributors and crew, and retrieving and reviewing relevant documentation and footage, including 85 hours of raw footage filmed for the series. Neither Love Productions’ investigation nor Channel 4’s internal inquiries revealed any evidence to support the allegations made about the programme.” At a meeting of the cross-party digital, culture, media and sport select committee on 19 May, Dorries made various allegations including that the reality show used paid actors, or acting students, and that some of the show’s participants did not live in the homes in which the series portrayed them as living. On Friday, Julian Knight, the chair of the DCMS select committee, said that it had asked Dorries for a response to the findings of the investigation “as a matter of urgency”. “The committee has written to the secretary of state on this matter and invited comments from her as a matter of urgency. Now that Channel 4 and Love Productions have concluded the investigation, we look forward to receiving the secretary of state’s response, which we will then publish.” On the reality show, Dorries was sent to live in an estate in South Acton, west London, sparking a minor scandal when the MP was revealed to have smuggled in a £50 note, which she claimed was intended to buy gifts for the children of her hosts. She told parliament she believed the hosts were planted by the show’s producers. “I discovered later they were actually actors,” she told MPs. “The parents of the boys in that programme actually came here to have lunch with me, and contacted me to tell me, actually, they were in acting school, and that they weren’t really living in a flat, and they weren’t real. And even, if you remember, there’s a pharmacist or somebody that I went to see who prepared food – she was also a paid actress as well.” Channel 4 said that it takes any allegations of misrepresentation “extremely seriously and always rigorously investigates any such claims”. It emerged on Tuesday that the DCMS had tried to intervene to alter the wording of Channel 4’s annual report to fit its privatisation plans for the broadcaster.