Former NBA star Lamar, who is the ex-husband of Khloe Kardashian, is currently being treated at Sunrise Hospital in Las Vegas and officials said there is no immediate word on his condition.
Sheriff Sharon A Wehrly said the Nye county sheriff's department was called at 3.15pm to Love Ranch in Crystal, Nevada about a report of an unresponsive man needing an ambulance.
Lamar, 35, had to be driven to hospital because the 6ft 10in former basketball player was too tall to be airlifted in the helicopter.
Dennis Hof, who owns the Love Ranch brothel in Nevada, told The Associated Press that Lamar arrived at the brothel on Saturday.
"He just wanted to get away, have a good time and relax," said Dennis, who claims Lamar had been allegedly taking herbal viagra and had drunk part of a bottle of cognac.
Lamar, who has had a long struggle with alcohol and drug addiction, split with Khloe in 2013 after four years of marriage.
Khloe and Lamar signed divorce papers July this year.
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