LOS ANGELES (AP) — Sacha Baron Cohen went undercover as his alter ego Bruno on Sunday by crashing a rally in support of a ballot measure that would ban gay marriage in California.

The British comedian is working on a film based on the fictional character Bruno, a gay Austrian fashion reporter who conducted gag interviews on HBO's "Da Ali G Show."

Cohen, in disguise in a blond wig and preppy outfit, marched with demonstrators who support Proposition 8 while being trailed by cameras in a rally across from City Hall.

When photographers and reporters realized who he was and tried to approach the star, members of his film crew tried to shield him, and he was eventually whisked away in a van.

Cohen, who has made a career out of filming unwitting victims of his fake identities, also played a journalist in the hit movie "Borat: Cultural Learnings of America for Make Benefit Glorious Nation of Kazakhstan."

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