But the e-mail message turned out to be a joke. Chilean Government officials confirmed that the Spaniards were both safe in La Serena, 500km north of the capital Santiago.

The two had sent an e-mail message to their family, saying they were being held by people angry with Spain for requesting the General's extradition.

However, a Chilean senator who broke the initial news, Sergio Bitar, later told Chilean television that the alleged victims had called their relatives to say it was a joke.

The two were named as economist Gonzalo Fernandez de Cordoba Lopez, 64, and his daughter Ana, 23.

The pair have been travelling round Latin America and were in constant e-mail contact with two of Mr Fernandez de Cordoba's daughters who live Chile.

Senator Sergio Bitar told Spanish radio that the e-mail asked for action to be taken if they did not appear on Thursday, but to do nothing for the time being.

The UK's Law Lords are due to decide on Wednesday whether General Pinochet has immunity from prosecution or whether he has to face an extradition appeal from Spain.