The naked body of Carlos Castro, 65, was found lying face-up in a pool of blood inside his 34th-floor room at the InterContinental New York Times Square on W. 44th St. about 7p.m., the sources said.
The prominent gay activist had been bludgeoned in the head and his scrotum cut off, sources said.
Several hours prior to the grisly find, Castro had a heated argument with his companion - Renato Seabra, a twentysomething Portuguese male model - sources and witnesses said.
The two checked in together on Dec. 29.
A female friend of the writer and producer grew concerned after she heard of the dispute and went to the swanky hotel to check on Castro, sources said.
Not knowing what room her pal was in, the New Jersey woman went to the front desk.
Suddenly, the tall, chiseled Seabra came through the lobby, recognized the worried woman and told her Castro "was not coming out of his room," a source said.
That's when she lost her cool.
"She was screaming hysterically," Hughes said.
"The hotel security did nothing except quickly push her out the door."
Soon after the bizarre scene, hotel staff went to room 3416 and made the gruesome discovery. They quickly called 911.
A couple staying in a room two doors down heard the two men arguing earlier in the day.
"There was a lot of noise, talking," said Suzanne Divilly, 40, who was celebrating her honeymoon in the city.
"You could hear them arguing in the corridor and even in our room," she said. "We didn't think anything of it, because it was none of our business."
Investigators believe the argument ended with Seabra grabbing a knife and slashing his partner's testicles, then repeatedly beating him with a piece of furniture, sources said.
Castro, aside from his gay rights advocacy, has worked for several television and radio stations in Portugal during his career, according to a biography page on his website. The site also notes his work for several national modeling competitions.
Police were still searching last night for Seabra, who once appeared on a Portuguese top model show.
They were canvassing local hospitals, thinking he was injured in the struggle.
"I can't believe it," said Hughes. "New York City was supposed to be where you could go anywhere and be safe."