(Agencies)
Updated: 2007-11-27 11:30

SAN JUAN, Puerto Rico -- Police on Monday sought to determine who tried to turn a beauty contestant ugly by dousing her clothing with a chemical solution and spiking her makeup, causing her to break out in hives.

Ingrid Marie Rivera smiles during a beauty pageant in Santurce, Puerto Rico, Friday, Nov. 23, 2007. Rivera beat 29 rivals to become the island's 2008 Miss Universe contestant, despite applying makeup and wearing evening gowns that had been coated with pepper spray, pageant spokesman Harold Rosario said. [Agencies]

Ingrid Marie Rivera was composed while appearing before cameras and judges throughout the Miss Puerto Rico Universe pageant but had to strip off her clothes backstage and apply ice bags to her face and body and she swelled and broke out in hives twice. But the veteran beauty-pageant contestant beat 29 rivals Friday to become Puerto Rico's 2008 Miss Universe contestant.

Pageant spokesman Harold Rosario said the symptoms first began showing up during preliminary competition on Nov. 18.

"We thought at first it was an allergic reaction, or maybe nerves," Rosario said. "But the second time, we knew it couldn't have been a coincidence."

Police spokesman Stephen Alvarez said Monday that an evening gown and Rivera's makeup have been delivered to the Institute of Forensic Sciences for a chemical analysis. Magali Febles, director of the Miss Puerto Rico Universe pageant, said earlier that the substance used in the alleged attempt to derail Rivera's bid for the crown appeared to be pepper gas.

Rivera tearfully recounted her ordeal at a news conference Sunday, acknowledging she had wavered about staying in the contest.

"At one point I said, 'Am I a masochist?'" she recalled. "But I said, 'I am with God and this is my goal, regardless of the results.'"

Rosario said he saw something was wrong days ago.

"We noted that when she finished applying makeup and went to get on stage, she began to get red in the face, on the back and shoulders -- everywhere she had applied makeup," Rosario said in a telephone interview from the Dominican Republic, where Rivera was participating in a fashion show Monday.

Pageant security agents, some of whom are former police officers, on Friday identified stains on Rivera's clothing as originating from pepper spray, according to Rosario.

Rosario said promoters and makeup artists of rival contestants are suspected of being behind the sabotage effort, but he did not name names.

From the beginning, Rivera's bid for the crown was contentious. Some of her rivals felt at a disadvantage because she was a veteran contestant, having been second runner-up in the 2005 Miss World contest.

A bag with Rivera's clothing, makeup, credit cards and other belongings had mysteriously disappeared for a while during the pageant, Febles said.

Beauty competitions in the U.S. Caribbean territory — which boasts five Miss Universe titles, second only to the U.S. — are fierce, drawing boisterous audiences and accusations of rigged results.