Saudi Arabia, which was chosen last week to head the UN Human Rights Council, is preparing to behead and crucify a young protester who was only 17 years old when he was arrested in 2011.

Ali Mohammed Baqir al-Nimr, a member of Saudi Arabia's Shi'ite minority, was convicted on charges including taking part in anti-government protests and attacking security patrols. UN human rights experts have said that he was tortured and did not receive a fair trial.

"Any judgment imposing the death penalty upon persons who were children at the time of the offence, and their execution, are incompatible with Saudi Arabia's international obligations," the UN group said in a statement on Tuesday.

The UN Convention on the Rights of the Child, to which Saudi Arabia is a signatory, forbids capital punishment for offences committed by people under the age of 18. However, all al-Nimr's appeals against the death sentence have failed.

Observers have pointed out that Eastern Province, where the protests occurred, has a Shia majority that has long protested of discrimination in the Saudi-dominated country.

Others have noted the irony of Saudi Arabia heading the UN Human rights panel. In a note on the al-Nimr case, Amnesty International says: "Saudi Arabia is one of the most prolific executioners in the world, putting more than 2,200 people to death between 1985 and 2015. Between January and the end of August 2015, it executed at least 130 people, almost half of them for offences that do not meet the threshold of 'most serious crimes' for which the death penalty can be imposed under international law."