Spanish authorities will remove Francisco Franco's remains from a state mausoleum on Thursday, seeking to exorcise the ghost of a dictator whose legacy still divides the country more than four decades after his death.

Amid tight security and in virtual secrecy, his coffin will be taken from the Valley of the Fallen and reburied in a private family vault, transported either by helicopter or, if bad weather intervenes, by guarded motorcade.

"It's intensely symbolic for Spain," said political scientist Pablo Simon, "because the (Franco) monument has always been connected to those who miss the old regime."