Joshua Loudermilk, one of two men apparently discredited by the new Ali G movie Ali G: Who Iz I ?, has said that he was in on the joke, but that the film-makers didn’t realise this.

Loudermilk, a 54-year-old aspiring actor from North Carolina, has told the Guardian he recognised star Sacha Baron Cohen early in the shoot but continued pretending to be a hard-right Maga sympathiser prepared to defend the US border at all costs.

The movie involves Loudermilk being recruited by another Cohen character, the ex-Mossad terrorist expert Col Erran Morad, to help form a citizens’ warrior force to protect US borders, making use of his top-secret new weapon: a gun disguised as buttocks.

Along with fellow recruit Michael Aboud, the chair of the El Paso county Republican party, Loudermilk joins Morad on a mission to stop the birth on US soil of the baby of a fictional South American drugs kinpin.…