The footage, gathered over the course of a year and broadcast by ITV News, also showed a former Reform candidate claiming he failed the party's vetting process twice but was still allowed to stand as a councillor. Reform denied the individual failed vetting in the first place.
In a statement, Reform said it had "improved and prioritised its vetting procedures" and that "from time to time, a handful of individuals who do not share our values will initially make it through vetting", adding: "This is the same for all organisations."
The latest footage follows undercover filming broadcast on Wednesday night which showed some of Reform's councillors and candidates using racist, violent and sexist language. The party said there was "no room for racism in Reform UK" and that it would not comment on individual cases while investigations were ongoing.
Reform also accused the ITV investigation of using "extreme methods of deception" and false information to obtain an undercover role in the party's headquarters.
The controversy comes two years after leader Nigel Farage vowed to vet candidates more "rigorously", after the party dropped a series of candidates following reports that they had made offensive or racist comments. The party has continued to face questions about the issue.