A third woman who partied with Charlie Sheen before he was taken by ambulance to the hospital has been identified as GiGi Rivera, RadarOnline.com has learned.

Rivera is a 19-year-old brunette porn star who got into the business when she was just 18 and brags on her XXX website that she's already starred in 50-60 adult films.

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"When she isn't having sex in her personal life or on screen, you can find Gigi smoking bowl after some high grade marijuana (her other passion)," the website boasts.

As RadarOnline.com previously reported, two woman have already been identified as having partied with Sheen at his mansion - Kacey Jordan, 22, and Melanie Rios, 19.

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Unlike Jordan, who partied with the Two and a Half Men star until Wednesday afternoon, Rios told friends she was with him when the 911 call was placed on Thursday morning at 6:35 a.m.

Sheen was released from Cedars-Sinai Medical Center on Thursday night after having been on an alcohol and cocaine bender.

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The 45-year-old actor had barely slept since Monday and was smoking and snorting cocaine.

As RadarOnline.com reported exclusively he was anemic with an elevated white blood cell count and dehydrated when taken to the hospital. Doctors suspect he has an ulceration.

Sheen's father, Martin Sheen, was at the hospital with his son and as RadarOnline.com reported, was urging him to check into rehab.

"Martin is extremely upset as you can imagine," a source close to the family told RadarOnline.com. "He's worried Charlie is going to kill himself.

"Martin has jumped in before when things got really bad with Charlie and even told a judge that Charlie needed rehab. He's not afraid to speak his mind."

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