Nick Brooks was a virtual unknown.
His father, Joseph, on the other hand, is a different story — an Oscar-winning songwriter who is now best known as an accused casting-couch sex fiend charged with assaulting a slew of starlet wannabes.
Yesterday, that all changed when the younger, unemployed Brooks, 26, was thrust into the spotlight after his gorgeous girlfriend, Sylvie Cachay, was discovered dead at the swank Soho House, where the pair had just checked in.
Cops had not decided last night if the death was a murder, and no one has been charged.
But Nick Brooks was hauled into the Sixth Precinct station house, where he spent most of the day being grilled by detectives as they scrambled to piece together elements of the case.
PHOTOS: SWIMSUIT DESIGNER SYLVIE CACHAY
Sources said he had been dating Cachay until Wednesday, just hours before her body was found face-up in a bathtub.
Prior to his meeting with cops at about 3:30 a.m., his only brush with publicity was in 2005, when he took out a full-page ad in The New York Times attesting to his father’s essential goodness in honor of his birthday.
“He really has made a profound difference in the world,” it said. “I wanted to tell it while he was still alive. He is the most talented, most daring, most tenacious man I know. He also gets me Knick tickets. I am proud to be your son. Happy birthday, Dad. Your loving son, Nick.”
Joseph Brooks soared to fame for writing and directing the 1977 movie “You Light Up My Life” and for composing the song of the same name that was the film’s signature.
The 72-year-old tunesmith was accused in 2009 of forcing himself on 11 women he lured to his home by promising them roles in films.
He faces an incredible 82 counts of rape, sexual abuse, criminal sexual act and assault.
In the Times ad, Nick Brooks recounted the never-before-told story of his father’s $2 million contribution to Memorial Sloan-Kettering Cancer Center, which was prompted by a story that appeared in Time magazine.
But the journal Oncology Times cast doubt on the veracity of Nick’s account a month later, in a piece that found “discrepancies unexplained, questions unanswered.”
A tall, quiet guy, the younger Brooks lives with three roommates in the East Village on Second Avenue near Houston Street.
Building superintendent Roddy Rodriguez told The Post that Brooks moved in about a year ago and, in the months since, the quartet’s fifth- floor, four-room pad has become a pig sty, with a hole in a door that was certainly not part of the renovation two years ago.
“He’s kind of aloof,” Rodriguez said. “It’s rare that we talk. He would just say, ‘Hi.’ ”
The curly-haired Brooks and his roommates are known by neighbors for partying late into the night at their $4,000-a-month spread and singing karaoke. The unmistakable aroma of burning marijuana wafts through the hallway, the super said.
But the idea that Nick might have murdered someone caught people off-guard.
“He didn’t look like a guy that had chutzpah to do something like that,” Rodriguez said.
Yesterday morning, Joseph Brooks was asked whether he had heard about his son’s predicament.
“I did,” he said, but would add nothing more.
Additional reporting by Jamie Schram, Ada Calhoun and Georgett Roberts