The case of Nancy Guthrie, the 84-year-old mother of US television presenter Savannah Guthrie, has entered a challenging phase due to hazy tensions between federal investigators and local officers, which threatens to complicate the already complex case.

More than a month after herdisappearance, law enforcement officers are still scrambling in the process of finding clues to how Guthrie vanished from her home near Tucson, Arizona.

It is also reported that some disagreements between the Federal Bureau of Investigation (FBI) and the Pima County Sheriff's Office are arguably delaying the investigation's advancement.

Nancy Guthrie was last seen in her Arizona residence on the night of 31 January, and detectives suspect she was kidnapped sometime after that. According to the investigators, the disappearance of the elderly woman is of concern because of her health status and reports about her critical medication being left behind at the property.

The FBI and the Pima County Sheriff's Department initiated a massive search operation that involved forensic teams, analysis of surveillance, and outreach to the community. At one time, the police blocked off the road in the neighborhood of Guthrie.

As part of the investigation, the sheriff and federal vehicles were entering and leaving the secured site, while police officers were going through potential evidence.

Although the investigation continues intensively, no suspects are officially identified, and the case itself has become one of the most discussed throughout the country.

The FBI has reportedly shown interest in a greater involvement in the investigation since the search seemed to stall.

According to reports, the federal agency intends to assume control immediately as the case is said to have reached a dead end, but was facing resistance from the local sheriff's department.

Separatereportingreveals that the point of disagreement revolves around the manner in which the major evidences are being handled.

Source: International Business Times UK