Spanish police have arrested a man thought to be a key figure in financing Osama Bin Laden's al-Qaeda network.

Syrian-born Spaniard Muhammad Galeb Kalaje Zouaydi, also known as Abu Talha, was detained in the Spanish capital, Madrid.

Police arrest Ahmed Brahim in Barcelona

The arrest follows the detention in Barcelona last week of Algerian Ahmed Brahim, who is suspected of being al-Qaeda's chief accountant in Spain.

The capture brings to 16 the total number of al-Qaeda suspects arrested in Spain since the 11 September attacks on the US.

Abu Talha is believed to have channelled money to a number of countries including Germany, where Mohammed Atta, who led the attacks, had been operating before 11 September.

Mohammed Atta is known to have visited Spain twice in the months leading up to the United States attacks.

Under surveillance

Other countries believed to have been part of Abu Talha's money web are Belgium, the United States, Saudi Arabia, Belgium, China, Turkey, Jordan, Syria and the Palestinian territories.

Abu Talha allegedly used a business in housing construction and sales as a cover.

Other arrests in Spain include Abu Dahdah, allegedly in charge of the group's infrastructure, and Abu Ilyas, who was resident in Germany and in close contact with Mohammed Atta.

The group had been under surveillance in Spain for almost two months before 11 September.

Observers say Spain's increasing use as an entry point for immigrants from the Muslim world makes it an ideal place for Islamic militants to operate in secret.