But six months after Saddam Hussein went to ground as US forces advanced on Baghdad, he remains at large and, in the view of most intelligence experts, somewhere in Iraq.

"Until we know differently, and I mean know conclusively, we are going to operate on the assumption that Saddam is probably still alive and somewhere in Iraq," said a US intelligence official speaking on condition of anonymity.

The words are backed with deeds.

Just this week, there was a scramble ordered at the main US military base in the former president's hometown of Tikrit, regarded as a key possible hiding place, after a report he had been sighted in a two-car convoy in the area.

Hurried checkpoints were set up along the length of the main Highway One leading north from Baghdad through Tikrit.

"It was just another Elvis sighting," sighed a member of the quick reaction force always on standby on Saddam watch.

"Elvis" is the nickname American forces have given to Saddam, a sardonic nod to the many far-flung "sightings" over the years of Elvis Presley who died in 1977.

The main speculation about where Saddam might have gone to ground has him hiding, disguised but in plain sight, in a major city like Baghdad or Tikrit, or skulking in a long-prepared bolt hole in the desert wastelands of northern or western Iraq.

There are also the man-in-the street conspiracy theories, derided by most analysts, that he did a secret exile deal with Washington or found refuge in neighbouring Syria or Iran.

Mustafa Alani, an Iraq analyst at London's Royal United Services Institute, said neither Iran nor Syria would risk giving him sanctuary.

He said money, which includes a $1 million bounty offered by American actor Bruce Willis on top of the $25 million offered by the US government, was not working partly because many Iraqis did not believe the rewards would actually be paid.

"The people giving him refuge have loyalty. It may be only three or four families passing him around," Alani said, adding that they feared the lasting stigma of betraying him for money.

On Baghdad streets, many people believe Saddam is hiding somewhere in the volatile "Sunni triangle," most probably in the Tikrit region where members of his tribe are protecting him.

"I am 100 per cent certain he is in Tikrit," said 26-year-old street vendor Saad Shuwayl. "The people there love him."