Officials pounced on the pair after Drag Me to Hell star Romero's ex-boyfriend exposed the alleged scam marriage to U.S. authorities, reports the New York Post.
Klinko, a Swiss photographer who starred in reality TV show Double Exposure, claims he dated Romero in 2007 while she was married to Ross.
The snapper is now expected to be the star witness in the pair's immigration fraud trial, which begins in Los Angeles on Tuesday (24Aug10).
The prosecution, bolstered by Klinko's testimony, will argue that Ross and Romero have never lived together and have continued to date other people since their 2005 nuptials.
They claim the groom was paid a $5,000 (£3,333) dowry to help his actress bride stay in the United States after the pair was introduced by fashion mogul Michael Ball.
The defence team will claim Klinko fabricated his story after Romero spurned him. Papers already filed accuse the photographer of becoming "obsessed with a young woman half his age, who, when spurned as her lover, was driven by spite and revenge to destroy her life, her career and her reputation."
The defendants, both 28, face up to five years behind bars if found guilty.