Peshawar, Pakistan: A court in Pakistan on Tuesday suspended a death sentence passed by one of the country's controversial new military tribunals, officials said.

Lawmakers voted in January to set up military courts to hear terrorism cases, prompting criticism from lawyers and rights activists concerned about the hearings, which are held in secret.

The Supreme Court backed the move earlier this month, rejecting claims it was unconstitutional, but said defendants had the right to challenge sentences in civilian courts.

The high court in the northwestern city of Peshawar, which has borne the brunt of the Islamist violence that has wracked Pakistan over the last decade, on Tuesday stayed a hanging imposed by a military tribunal.

‘The Peshawar High Court has ordered the military court to halt the execution of my client Haider Ali, who was awarded the death sentence by a military court on 13 August,’ Ajmal Khan, lawyer of the death row convict told AFP.

Khan said the military personnel came to visit Ali's parents to inform them of the sentence but did not say what the conviction was for.

On the same date, the military announced the death penalty for six militants linked to an assault on a school in the northwestern city of Peshawar that killed 151 people in the country's deadliest terror attack, but Ali's name was not included on that statement.

He said Ali was handed over to the military in 2009 by a local council of elders, known as a jirga, and his family has not heard from him since.

‘The family of my client was never allowed to meet him since the military took him into custody in 2009 -- they won't even say anything about where he is to his parents,’ he said.

Khan said the family only heard about the death sentence through the media.  

‘My client was a grade 10 student at the time of his arrest and was around 15 years old,’ he said.  

A court official confirmed details of the case, saying Ali was listed as a missing person and a petition for his recovery had been with the court for five years.  

The military courts were established as part of a crackdown on militancy following the massacre at the Peshawar school on 16 December last year.

Parliament has approved the use of the courts for the coming two years, and cases are referred to them by provincial governments.

But some have called for the trials to be more transparent.

The International Commission of Jurists has condemned the military courts as ‘secret, opaque’ and in violation of fair trial obligations.