Investigations to ascertain if a fidayeen (suicide) team was involved in the July 11 Mumbai serial blasts were hampered as the only unclaimed body in the blasts, currently lying at the Sion Hospital mortuary, remains unclaimed, sources said.

The involvement of a fidayeen squad in the blasts was one of the angles which the Anti Terrorism Squad had been probing, the sources said.

Speculation over the involvement of a fidayeen squad was fuelled by an e-mail received by a television channel from an organisation identifying itself as the Lashkar-e-Keher, which claimed that one of its members was killed in the blasts.

ATS chief K P Raghuvanshi had earlier told reporters that two perons had visited the mortuary in search of their missing kin, and one of them told the authorities that he would return with family members to check if the body was that of his relative. He never turned up after that, the sources said.

The police have also prepared a digital sketch of the victim from the body remains.

"I urge people who have their kin missing in Mumbai after the blasts, to have a look at the body or the sketch and help the police identify the victim," Raghuvanshi told reporters.

ATS sources said the police was exploring the theory of a fidayeen squad's involvement since the unclaimed victim's body has only the upper torso intact, while the lower portion was completely destroyed in the blasts. This is usually the case when someone is very close to the explosive device or himself exploded the device, sources said.