NO MERCY: He is waiting for his dad to pardon him for beating up on his stepmother

A Saudi Arabian man who was jailed for three years in 1997 has spent a further 12 years behind bars waiting for his father to pardon him, a local human rights group has said.

Eid al-Sinani, 43, was originally sentenced to three years in prison and 200 lashes for beating up his step mother, Musab al-Zahrani, a researcher at the National Society for Human Rights (NSHR), told Reuters.

However, when the sentence had been served the father asked a judge to keep his son in prison "until he is proven to be righteous by his father".

The judge agreed and 12 years later Sinani is still in jail, Zahrani said.

Under the kingdom's Islamic legal system, law is not systematically codified and judicial rulings are subject to individual judges' interpretation of sharia.

Some judges view children's "disobedience" towards their parents as an offence worthy of lashing and even jail sentences.

Rulings in Saudi Arabia are not based on precedent and, even with the same charge, they can differ from one judge to another.

"We are optimistic that he will be released because he has been jailed for (almost) 16 years and there is no real charge… This is legally problematic because they gave absolute power to the father and the son is left under his mercy," Zahrani said.