A man detained in southern Arizona in connection with the disappearance of 84-year-old Nancy Guthrie was released after questioning, as authorities searched his Rio Rico home.

The Pima County Sheriff’s Department and FBI have not confirmed his identity but said the home searched is believed to belong to the man detained.

Family members said law enforcement entered the house and took him into custody, though it remains unclear what prompted the traffic stop that led to his detention.

The development came hours after new activity was recorded in a cryptocurrency wallet linked to a ransom note sent to local media, AZ Family has reported.

Guthrie has been missing for 10 days, and the FBI has identified an armed, masked man seen on surveillance video outside her Tucson-area home as a suspect.