Gloves found near Nancy Guthrie’s home in the Tucson area could prove pivotal for police tracking down a suspect in the 84-year-old's disappearance, according to a retired FBI agent.

A local sheriff is impeding FBI access to key evidence in the Nancy Guthrie abduction probe, a law enforcement official with knowledge of the case has said.

A man, whose identity remains unconfirmed, claimed he was briefly detained and questioned in connection with her disappearance.