The owner of the Harvard Square hair salon About Hair, already charged with running a prostitution ring out of the store, pled not guilty on Tuesday in Cambridge District Court to a new, separate charge of rape.

According to Middlesex District Attorney (D.A.) Spokeswoman Melissa Sherman, Duncan W. Purdy, 52, also pled not guilty to a new charge of indecent assault and battery of a person over 14 years old at his arraignment yesterday.

He was released without bail, and is due back in court on May 5 for a pre-trial conference, Sherman said.

Purdy was first arrested in early October of last year after an undercover sting operation by the Cambridge Police Department and Somerville Police Department alleged that he was running a prostitution ring out of his salon and antique store on Arrow Street.

In December, he was indicted by a Middlesex grand jury on charges of maintaining a house of prostitution and deriving support from a house of prostitution.

And earlier this week, Purdy was indicted on new charges that he allegedly raped a then-19-year-old customer in March 2004.

The woman claims that he touched her “inappropriately and raped her” during a scheduled massage, according to a Middlesex D.A. press release.

Purdy told The Crimson on Monday that he was not guilty.

“I am not guilty of the charges,” he said. “I’ve been here for 20 years, and my whole life has been helping people. I have basically been a servant. I cut people’s hair."

—Staff writer Reed B. Rayman can be reached at rrayman@fas.harvard.edu.