Police in Puerto Rico said Wednesday they expect to arrest two people in connection with a plot to sabotage a beauty pageant contestant by dousing her clothes with pepper spray.

The two pageant employees — the security director and a catwalk co-ordinator — allegedly coated clothing and makeup belonging to beauty queen Ingrid Marie Rivera with pepper spray in an attempt to help a rival at November's Miss Puerto Rico Universe competition.

The 24-year-old Rivera, who won the pageant, maintained composure onstage but later swelled up and broke out in hives.

An investigation into the incident found that a black gown and a bathing suit worn by the beauty queen in the competition's final round tested positive for pepper spray. Earlier, a different dress and makeup brush tested negative.

Investigators said the items were likely sprayed when contestants and assistants left the changing room.

Police spokesman Lt. Eddie Hernandez said Tuesday that the pair would likely be charged with assault.

Pageant organizers will screen volunteers and employees more carefully in the future, director Magali Febles said.

With files from the Canadian Press