Dennis Hof, in the brothel with legal prostitutes Chantel Baby and Maggie Monroe in Nevada

An investigation of three legal Nevada brothels owned by a reality TV star and candidate for the state legislature found immigration violations and indications of possible human trafficking, the county sheriff said.

An inspection this week of the Bunny Ranch, Kit Kat Ranch and Love Ranch, all owned by Dennis Hof, capped a four-month probe by the Lyon County Sheriff's Office and U.S. Immigration and Customs Enforcement, Sheriff Al McNeil said in a statement.

Hof, who appeared in the HBO reality TV show "Cathouse" about prostitutes at one of his brothels, won the Republican state primary in June for a seat in the Nevada assembly and is considered the favorite in the November general election.

Hof denied any immigration violations or trafficking at the brothel and said the sheriff's department was responsible for screening prospective employees.

"It's on the county, not us," Hof told Reuters.

Nevada is the only U.S. state where prostitution is legal, although it is confined to brothels in eight counties.

"The discovery of U.S. immigration law violations in our legal brothel system is extremely alarming," McNeil said in a statement posted on Facebook on Thursday.

"The ability to coerce, exploit and traffic non-US citizens into Lyon County by foreign criminal enterprises is going to be difficult to detect and deter by our limited capabilities and resources of foreign born applicants, which has caused us to develop better working partnerships with federal agencies to combat human trafficking efforts," he said.

Lyon County Sheriff deputies and U.S. Customs and Immigration officials this week conducted an inspection of work cards required for prostitutes at Nevada's brothels, McNeil said.

A four-month-long internal investigation found prostitute registration procedures to be rife with violations over several decades, the sheriff's office statement said.

"Those practices include US immigration law violations, foreign country human trafficking indicators, fraudulent statements, issuance of work cards prior to completing criminal history background checks, and inability to validate out-of-state and US and other foreign national documents to determine identity," the statement said.

© Thomson Reuters 2018