DENVER -- A pile of deer-mice feces is holding up an investigation into the deaths of a man and woman whose bodies were found along the San Juan River in 1982.

FBI agents are postponing the testing of blood found in a decaying bus near the New Mexico-Colorado state line, near where the bodies were found, because the evidence may be infected with hantavirus.

The respiratory illness can infect humans who inhale dust contaminated with excrement of deer mice.

Archuleta County sheriff's detective George Barter said it's a temporary problem. He said that once infected dust is removed, it is only contagious for about five days.

After that, blood found in the bus will be tested to see if it matches either victim.

Authorities searched the bus last year after a man came forward and told authorities where to find it. He said it was where the two unidentified victims were slain.