COLUMBUS, Ohio -- Cleveland kidnapper Ariel Castro may have died from auto-erotic asphyxiation, not suicide, and two prison guards falsified logs documenting their observation of him in the hours before he died, the state said Thursday.

Castro's pants and underwear were pulled down to his ankles when he was found, leading the state to forward those facts to the state highway patrol to consider the possibility of auto-erotic asphyxiation, according to the report from the Ohio Department of Rehabilitation and Correction.

The report suggests -- but does not conclude -- that Castro may have died as the result of auto-erotic asphyxiation, whereby individuals achieve sexual satisfaction by briefly choking themselves into unconsciousness.