MULTAN: A Pakistan court has jailed a Muslim prayer leader and his 20-year-old son for life on controversial blasphemy charges in the rural centre of the country, court officials said Tuesday.

The case follows the killing of Punjab provincial governor Salman Taseer by his bodyguard last Tuesday, after the outspoken politician called for reform of the law that was recently used to sentence a Christian woman to death.

Mohammad Shafi, 45, and his son Mohammad Aslam, 20, were arrested in April last year for removing a poster outside their grocery shop advertising an Islamic event in a nearby village which allegedly contained Quranic verses.

Judge Mohammad Ayub, heading an anti-terrorism court in the central Pakistani town of Muzaffargarh, handed down a life sentence to the pair on Monday, his assistant Faisal Karim told AFP by telephone.

The prosecution alleged organisers of the event, which commemorated the anniversary of the Prophet Mohammad's birth, said the pair had “pulled the poster down, tore it and trampled it under their feet,” Karim said.

“The judge sentenced them to life imprisonment on charges of blasphemy and ordered them to pay a fine of 200,000 rupees ($2,350) each,” he said.

Liberal politicians and human rights activists in Pakistan say the blasphemy law, which carries the death penalty for the worst offences, is sometimes used to settle personal scores and encourages extremism.

Defence counsel Arif Gurmani vowed to challenge the verdict in the high court because “it has been given in haste” and was the result of inter-faith rivalries, he said.

“Both are Muslims. The case is the result of differences between Deobandi and Barelvi sects of Sunni Muslims,” he said.

“Shafi is a practising Muslim, he is the imam of a mosque and he had recently returned from a pilgrimage to Saudi Arabia.... I am defending them because I am convinced they are not guilty of blasphemy,” he said.

Nobody has been executed in Pakistan for blasphemy and those given the death penalty have so far had their sentences overturned or commuted on appeal.

Since Taseer's assassination, right-wing religious clerics have heaped praise on his killer and stoked controversy over reform of the law. The government has said it has no plan to reform the law.

The controversy was sparked when former information minister Sherry Rehman tabled a private member's bill in November, seeking to abolish the death penalty for blasphemy.