Jailed Dutchman Joran Van der Sloot in a hunger strike over decision to move him to a maximum-security prison

JORAN van der Sloot has gone on a hunger strike over a decision to move him to a maximum-security prison after he reportedly threatened to kill a guard.

Van der Sloot is reported to have threatened to kill the warden of the Peruvian prison where he was serving a 28-year term for murder.

Prison officials said Van der Sloot made death threats against the warden after guards confiscated a mobile phone he had smuggled into his cell.

Serving 28 years ... Joran van der Sloot has been moved to a maximum-security prison. Source: AP

However Van der Sloot said the mobile phone was given to him by the warden as "a setup”.

His lawyer said the Dutchman had "a problem with the director” of the Piedras Gordas prison on the outskirts of the capital, Lima, where he had been held.

Peruvian prison spokeswoman Janeth Sanchez said the 27-year-old Dutchman was moved on Sunday to Challapalca, located high in the Andes near the Bolivian border. He previously was held at a prison north of Lima.

Still missing ... Natalee Holloway of Mountain Brook, Alabama. Source: AP

Van der Sloot was the last person seen with US teenager Natalee Holloway, who vanished while on a graduation trip to Aruba. He is imprisoned for killing Stephany Flores, a 21-year-old Peruvian business student in 2010. He married his pregnant Peruvian girlfriend in a prison ceremony last month.

Murdered ... Stephany Flores was killed by Joran van der Sloot. Source: AP