A group of British plane spotters arrested in Greece on espionage-related charges had already photographed two other air bases.
The 14 aviation enthusiasts – 12 Britons and two Dutch nationals – were remanded in custody yesterday after testifying before a Greek magistrate.
They were arrested on Friday in Kalamata, 149 miles south-west of Athens, after attending an event to mark an air force holiday at a military airfield.
A government spokesman, Tilemahos Hitiris, said: "They were taking pictures of a military base. The film was confiscated, they were arrested and then brought before an investigating magistrate."
Greek intelligence officers are expected to travel to Kalamata today to analyse the film, after which judicial authorities will decide whether to set a trial date or drop the charges. Until then, the group is to be held in police facilities in Kalamata.
Authorities said that after their arrest, military investigators found the group to be in possession of photographs of two other military bases – at Tanagra near Athens, and the Nato base at Araxos in southern Greece.
The 11 men and one British woman were named as Paul Coppin, 45, Mick Keane, 57, Steve Rush, 38, Anthony Adamiak, 37, Graham Arnold, 38, Michael Bursell, 47, Lesley Coppin, 51, Gary Fagan, 28, Wayne Groves, 38, Andrew Jenkins, 32, Peter Norris, 52, and Christopher Wilson, 46. The group was travelling on an excursion organised by Touchdown Tours, based in Mildenhall, Suffolk, which organises trips to air shows and air force facilities around Europe.
Greek authorities have frequently detained and released tourists for photographing military installations. Last month, four Israelis were arrested on Crete after inadvertently videotaping installations of a navy base. They were later released.
Don Groves, whose son, Wayne, of Tamworth, Staffordshire, was among those arrested, said he had spoken to him on Friday. "He said he had been accused of looking at buildings, whatever that means."
Another British detainee told his father he felt optimistic he would be released by the Greek authorities because "he had not done anything wrong".
Edwin Jenkins, from York, said his son, Andrew, a factory worker, was "in high spirits" when he telephoned. "He should be released because he did nothing wrong, " Mr Jenkins said.