Demonstrations against blasphemy charges in Lahore.

Demonstrations against blasphemy charges in Lahore. Photo: AP

Lahore: A court in Pakistan has passed a death sentence on a man convicted under controversial blasphemy laws of insulting the Prophet Mohammed, lawyers said on Tuesday.

Pakistan has strict laws against insulting Islam, which can sometimes carry the death penalty, but rights activists say they are often misused to settle personal disputes.

Zulfiqar Ali, aged in his 50s, was arrested in April 2008 in the eastern city of Lahore and accused of writing blasphemous slogans on walls.

Ali's lawyer said his client was insane but Judge Naveed Iqbal passed the death sentence on Monday, prosecution lawyer Chaudhry Ghulam Mustafa said.

The country has had a de facto moratorium on civilian hangings since 2008. Only one person has been executed since then, a soldier convicted by court martial.

"Accused Zulfiqar Ali has committed the act of blasphemy by writing the abusive sentences towards Holy Prophet on the walls of Nehru Park, Islampura," the judge said in his ruling.

"He was caught red-handed. Police came there. He was also used to utter derogatory remarks on hearing the call for prayers."

Ali also must pay a fine of one million rupees ($A10,812), otherwise he will have to spend one year in jail before going to the gallows, the order said.

Defence lawyer Kashif Ali Bokhari said Ali was brought to court from the psychiatric ward of the jail.

"I pleaded in the court that he was insane but this plea was ignored," Bokhari said.

The judge in his order said he checked Ali and found him mentally competent.

Blasphemy is a hugely sensitive subject in Pakistan, where the majority of the 180 million population are devoutly Muslim.

Even unproven allegations can provoke a violent public response.

A recent report from a US government advisory panel said Pakistan used blasphemy laws more than any other country in the world. It listed 14 people on death row and 19 others serving life sentences for insulting Islam.