Qari Abdul Hayee, popularly known as Asadullah and from Karachi’s eastern Gulshan-e-Iqbal neighborhood, was detained in a raid on his hideout on Sunday, said a spokesman for the Rangers paramilitary force.
Asadullah was formerly chief of the sectarian group Lashkar-e-Jhangvi (LeJ) in the southern province of Sindh and was “involved in several terror acts”, said the official.
“He was also in the picture about US journalist Daniel Pearl’s murder case,” the spokesman said without elaborating.
Pearl, 38, was the South Asia bureau chief for The Wall Street Journal when he was abducted in Karachi on January 23, 2002, while researching a story about Islamist militants.
A graphic video showing his decapitation was delivered to the US consulate in the city nearly a month later.
The spokesman said that in 2003 the group led by Asadullah had sent parcel bombs to police officers, injuring many people.
In December 2002 the same group planned a suicide attack on a hotel near Karachi airport where US soldiers were staying, the spokesman said. But the bomb exploded while being prepared and killed an associate of Asadullah.
The Rangers spokesman said the suspect would be handed over to police after further investigation.
Police last Thursday arrested six Taliban militants in Karachi’s southern and western neighborhoods and seized explosives and weapons.
Among those held was a man called Bashirullah, described as a mastermind of a bombing in the city’s Shiite neighborhood of Abbas Town, which killed 50 people and injured more than 100 on March 3.
Pakistani police blamed Pearl’s kidnapping and beheading on a group of Islamic militants headed by Ahmed Saeed Sheikh, also known as Sheikh Omar.
The British-born extremist was arrested with three others and convicted in June 2002 of Pearl’s murder by an anti-terror court.
Seven co-accused were sentenced in absentia and two of them were later killed in encounters with police.
Court documents said the men masterminded Pearl’s kidnapping in an attempt to win freedom for Al-Qaeda members imprisoned at Guantanamo Bay.
Omar and three others who were jailed for life lodged appeals that are pending in Sindh province.