Local news media reported that the pictures first appeared on Grindr, a mobile network application for gays and bisexuals, and that they themselves later received copies from unidentified sources.
Sen. Roberto Arango, who represents the capital of San Juan in the U.S. territory's Congress, did not categorically confirm or deny the photos are of him during an interview with WAPA TV earlier this week.
"I really don't remember having taken those pictures of myself, but it doesn't mean I didn't take them," he said. "I really don't remember."
Arango, who is single, said he has taken pictures of himself with a cell phone as he continues to lose weight.
He did not return calls for comment Saturday.
One picture depicts a nude torso and is reminiscent of images that led to the resignation of U.S. Rep. Anthony Weiner of New York and a county legislator in New Jersey earlier this year. The other pictures, taken from behind, show a nude man on his hands and knees.
Puerto Rican Gov. Luis Fortuno has said that if the man is indeed a legislator, he should resign, echoing the sentiments of other lawmakers, including local House of Representatives Speaker Jenniffer Gonzalez.
On Friday, Senator Carlos Javier Torres said in an interview with Radio Isla that the Senate ethics committee he leads will discuss the pictures in its meeting next week. He called the images worrisome and said they have caused great discomfort to many.
The committee is not launching an investigation into the pictures, however, his spokeswoman, Wanda Nazario, told The Associated Press later Friday. She said Torres was not immediately available for comment, and she didn't return calls for comment on Saturday.
Senate President Thomas Rivera Schatz said anyone is welcome to file a complaint if they have concrete information about the man's identity, but he reiterated that he will not call for an investigation himself.