Story highlights More are believed to be involved in sisters' deaths, police tell CNN affiliate

One of those arrested is beauty queen's sister's boyfriend, family tell police

The boyfriend had the most contact with the two sisters, police say

María José Alvarado Muñoz was set to head to London to participate in the pageant

(CNN) A Honduran beauty queen and her sister were found dead Wednesday, police said, and the sister's boyfriend and another man have been arrested in connection with the case.

The bodies of María José Alvarado Muñoz, the reigning Miss World Honduras, and her sister, Sofia Trinidad Alvarado, were found in a mountainous area beside a river after they had been missing for several days, Honduran police said in comments aired by CNN affiliate Televicentro.

Plutarco Antonio Ruiz Rodriguez and Aris Valentin Maldonado Mejia are now in police custody, and investigators believe more people are involved in the sisters' deaths, Police Commissioner Rolando Casco Torres told Televicentro.

The sisters disappeared last Thursday night after going to a spa for a birthday party for Ruiz in Santa Barbara, northwest of the capital of Tegucigalpa, police told CNN en Español.