A Washington man was convicted by a federal jury here yesterday of operating a prostitution ring in his massage parlor and some hotels here.

Roy Campbell, 30, of 3311 Porter St. NW, was convicted on the testimony of four admitted prostitutes - including a girl who was 16 when she said she "turned tricks" in the massage parlor and another girl who was 17 when she worked as a prostitute in hotel bars here.

Campbell is the first massage parlor operator to be convicted in D.C. in connection with alleged acts of prostitution at his place of business. The massage parlor, at 915 12th St. NW, is closed.

Testimony at the trial before U.S. District Court judge Barrington D. Parker, provided a behind-the-scenes look at the operation of the 915 Health Club and the acts of some of its masseuses in providing "complete" body rubs, performing sexual acts, watching X-rated movies with customers, and occasionally performing what they called "dominant" or "English" massages, in which customers would ask to be beaten with a whip before having sex.

One of the witnesses testified that she received no training on how to give massages, adding that "it just came natural."

Campbell was convicted on 10 counts, including bringing women across state lines for immoral purposes, enticing a minor female, and inducing women to engage in prostitution. None of the women claimed they were forced to engage in prostitution by Campbell against their will.

Campbell said in his own defense that any acts of prostitution committed by the women without his knowledge and approval.