A prison warden is said to have helped a suspected murderer to escape from custody in the US southern state of Alabama.

An arrest warrant has been issued for Vicky White, Lauderdale County Sheriff Rick Singleton said Monday.

The 56-year-old is accused of "allowing or facilitating the escape of unrelated Casey White".

The authorities have been searching for the prison guard and the alleged murderer for days.

Vicky White had picked up Case White from the Lauderdale County Jail on Friday morning - allegedly to take him to court for a psychiatric evaluation.

However, the two never arrived at the court and disappeared.

It soon became clear that there had never been such an appointment.

Vicky White also broke a rule requiring dangerous offenders to be accompanied by at least two officers.

Was the act planned?

There is "absolutely" a possibility that the two would have a relationship, Sheriff Singleton said at a news conference.

But this is not certain.

"We know she attended," the sheriff said of the inmate's escape.

"Whether she did it willingly or was somehow coerced or threatened into becoming a part of this outbreak is not really certain."

Vicky White convinced her colleagues Friday morning that she was the only officer with a firearms license available to bring the six-foot-tall, 250-pound inmate to court, Sheriff Singleton said.

The 38-year-old was then placed in a patrol car with handcuffs and ankle cuffs.

The car was later found empty in a parking lot.

According to the authorities, there are several indications of complicity on the part of the supervisor.

Friday was her last day at the job - she was supposed to retire then.

She had also sold her house about a month earlier.

The US Marshals Service, which is responsible for tracking down fugitives, on Sunday offered a $10,000 reward for information on the whereabouts of Case White and Vicky White.

The prison guard was still classified as "missing and at risk" at the time.

Case White confessed to the 2015 murder of a 58-year-old woman in 2020.

At the time of the confession, he was already serving a 75-year prison sentence for other crimes.

Authorities describe him as "extremely" dangerous.

"He has nothing to lose," Sheriff Singleton said.