New York (CNN) -- A swimsuit designer found dead in the bathtub of an exclusive Manhattan hotel was strangled and drowned, the New York City medical examiner's office told CNN Thursday.
The bruised body of Sylvie Cachay, 33, was discovered at the Soho House club and hotel December 9. Her death was ruled a homicide, according to medical examiner spokeswoman Grace Brugess.
Her boyfriend, Nicholas Brooks, was arrested and charged with attempted murder and strangulation, police said.
The details of his indictment are sealed and will not be revealed until his next court appearance on January 4, said Manhattan District Attorney spokeswoman Joan Vollero.
Brooks, whose father, Joseph, is the music director who produced the song "You Light Up My Life," has pleaded not guilty.
His attorney, Jeffrey C. Hoffman, said Brooks believes at least one other person had been in the room.
"I believe he is, in fact, not guilty," Hoffman said.
According to court documents, police said the only person in the hotel room with Cachay, besides Brooks, was a hotel employee who delivered ice and was inside for about one minute.
Brooks escorted the employee into the room and remained after the worker left, police said.
Authorities said they relied on interviews with hotel employees and surveillance videos from the location.
Police said they are investigating a time frame in which the killing occurred.
Cachay's body sustained bruising on the neck and bite marks, and was found clothed in the hotel room bathtub, police said.
An autopsy indicated that the designer suffered injuries that were consistent with neck compression, court records show. Cachay suffered internal hemorrhaging, injuries to her scalp and cuts to her lips and mouth, the documents said.
"Sylvie Cachay was one of those rare individuals who truly sparkled when she spoke," said publicist Kate Godici. "She will be deeply and painfully missed, yet celebrated, honored and never forgotten."