According to the FIR registered by police, Sheikh and his son Shahrukh were intercepted by four to five men travelling in a red pick-up truck and a motorcycle yesterday morning.
The armed men then bundled them into the pick-up.
Sheikh said the kidnappers did not talk to him or his son while they were in captivity.
The men, who were armed with sophisticated weapons, assaulted Sheikh and dumped him on Sheikhupura Road, 40 km from Lahore.
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Sheikh told police that the kidnappers were wearing 'shalwar-kameez' and were fluent in Pashto. They also spoke Urdu.
"They didn't talk to me and my son," Sheikh said.
He further said police that he did not suspect any intelligence agency or anyone else was involved in the kidnapping.
Sheikh needed six stitches for a wound on his head.
Police registered a case against unidentified men under Section 365 of the Pakistan Penal Code, which relates to kidnapping a person with intent to secretly and wrongfully confine him.
Sheikh was the lawyer for Sarabjit, who died on May 2 after being comatose for nearly a week following a brutal assault by other prisoners in Lahore's Kot Lakhpat Jail.
The lawyer recently said that he had been receiving threats for defending Sarabjit, who was sentenced to death for alleged involvement in a string of bomb attacks in Pakistan's Punjab province in 1990.