Pakistani police dug up a grave yesterday revealing a torso and severed head but said they were still unsure if the body was that of murdered US Wall Street Journal reporter Daniel Pearl.

Information Minister Nisar Memon cast doubt on initial reports that the body was Pearl`s, saying he believed this was not the case.

The remains were found in a nursery garden next to a small building where Pearl had apparently been held hostage on the outskirts of the southern port city of Karachi.

The police chief of Sindh province, of which Karachi is the capital, said the body was so decomposed "it cannot be identified".

"We are relying on DNA tests, which may take a couple of days or weeks," police Inspector-General Kamal Shah told a news conference.

A senior police official earlier told Reuters nine pieces of the body and hair were found "strengthening our belief that the body belonged to Daniel Pearl".

But Shah later said 10 pieces of the body were uncovered but no weapon that could have been used for murder was found in the compound.

"I think it is not the body of the Daniel Pearl that everybody seems to be talking," Information Minister Memon told Reuters Television in the evening on his arrival at Karachi airport from the Punjab province capital Lahore.

Officials said samples had been taken away for DNA testing. British-born Islamic militant Ahmed Omar Saeed Sheikh and three other men are on trial for their lives on charges of kidnapping and murdering Pearl. All four have pleaded not guilty.

Pearl disappeared in Karachi on January 23 while investigating links between Osama bin Laden`s al Qaeda movement and suspected shoe-bomber Richard Reid.

Pictures of Pearl holding a newspaper with a gun held to his head were later e-mailed to media organisations.

An investigator who helped dig up the grave site, near the town of Gaddap on the Karachi outskirts, said the body was lying on its back and the head had been placed in an upright position, balanced on the base of the neck.

The body had decomposed but it appeared the torso had been whole when buried. The grave was surrounded by date trees and other plants. The nursery was surrounded by desert.

In February, a gruesome three-minute video was delivered to US officials in the city showing Pearl dead.

The senior police official said they had found the room where Pearl was believed to have been held hostage inside the nursery.

"There`s a small one-roomed building inside the compound and that room has matched the room where the Daniel Pearl photographs were taken," he said.

"We will conduct tests on the hair, skull and teeth to cement our belief."

Manzoor Mughal, senior superintendent of police in charge of the investigation, said the face was not identifiable.

"I can`t say anything because his face is not clear. We have taken parts of the body for DNA tests," he said.

"We have also recovered some of the clothes, especially the sleeve of the T-shirt and the colour of the sleeve is blue."

In the picture of Pearl holding the newspaper, the T-shirt is not visible, but his windbreaker appears red and black with light blue sleeves.

It was unclear how the grave was found, but sources said there appeared to be a link with the arrests of three men following last week`s suicide bomb attack in Karachi on French naval engineers, which killed 14 people, including 11 Frenchmen.

Shah said the grave was found after a "tipoff from our sources" that prompted meetings through the night.

Two US officials were present when the body was exhumed at the nursery under tight security.

The closed-door Pearl trial began in Karachi on April 22 and was originally expected to last seven days. It has been plagued by adjournments and squabbles between defence and prosecution teams.

It was subsequently shifted to Hyderabad, 160 kilometres northeast of Karachi, after chief prosecutor Raja Qureshi said there were threats that the jail where the makeshift anti-terrorism court was located could be attacked.

Prosecutors say Sheikh Omar masterminded the kidnap, while the three other accused - Salman Saqib, Sheikh Adil and Fahad Naseem - were acting on his instructions.

Sheikh Omar was identified in court by two prosecution witnesses as having been seen with Pearl immediately before his disappearance.

Much of the prosecution case against the four men rests on the two e-mails sent to media organisations after Pearl went missing. The e-mails threatened to kill the reporter and contained photographs of him.