Security officials have named the man as Muhammad Jamil, and say that he was a likely suicide bomber in the attack targeting the president.
Aljazeera.net correspondent Imtiaz Gul says police believe that they have evidence of Jamil's involvement in the blast.
"A man's head was decapitated in the blast. Police believe that the head belongs to Muhammed Jamil and are using the latest technology to confirm if he was involved in the attack."
Pakistani Information minister Shaik Rashid confirmed the police enquiry.
"Investigators are trying to match his (Jamil's) face with the suicide bomber who was killed during the attack," he said
"One of the two suicide bombers who attacked the president's motorcade on Thursday is suspected to be a member of a wide network of religious extremists," he added.
He said preliminary investigations showed the second suicide bomber was probably a foreigner or an Afghan, adding that several people had been rounded up for questioning.
Security officials in Pakistan-administered Kashmir said three suspects were detained late on Friday in connection with the attack.
"One of the two suicide bombers who attacked president's motorcade on Thursday is suspected to be a member of a wide network of religious extremists"
Pakistani Information Minister
Newspaper reports, quoting unnamed security sources on Sunday, said Jamil had links with a network of jihadi organisations and that preliminary investigations had found he was in his mid-30s and estranged from his family.
Musharraf escaped unhurt on Thursday when suicide bombers driving cars packed with explosives rammed the Pakistani leader's motorcade at a petrol station, two kilometres from his residence in Rawalpindi, near the capital Islamabad.
Officials said 15 people, including the two suicide attackers and four policemen, were killed and 45 others injured.