PAUL WINDER upturns a black binliner on the table between us. A pile of clothes spills out: an olive green T-shirt pock-marked with gashes, a pair of frayed hiking trousers with red and blue patches and a pair of slashed and shredded boxer shorts decorated with the manically laughing image of Daffy Duck.

“I’ve never washed them,” he says earnestly. “I keep them in my parents’ loft. But this is what I wore. Torn to pieces but you can still smell the jungle.” Yes, there is a briary rankness to this dejected little heap: rich, vegetative, musty. Why keep them, though? “To remember what the conditions were like,” he says stoutly, “the reality of what we went through.”

On March 16, 2000, Winder, then 29, and his travelling companion Tom Hart Dyke, 24, were travelling over a notoriously dangerous part of the Colombia-Panama border, the Darién Gap, when they were seized by guerrillas. Their captors insisted the pair were CIA agents and held them for nine months in a series of mountainous jungle hideaways, demanding a ransom of $10 million (£6.8 million).

In fact Winder, an inveterate traveller, was out for a last hurrah before settling down to a “normal life” as a City trader, and Hart Dyke, a plantsman from Kent, was there to record — though, mindful of stringent international laws, not to remove — rare species of his favourite flower, the orchid. Their nine months were a mixture of hell (Winder almost lost his leg because of infection, they both feared they would be killed) and farce (Hart Dyke drove his kidnappers potty with demands that he must be allowed to search for rare orchids).

They are eccentrics, though very different. Hart Dyke is truly, madly devoted to plants and botany, talking in bug-eyed, staccato bursts about eucalyptus trees and alpine habitats. Winder, who was born in Zambia, is more measured, devoted to “always looking for somewhere that hasn’t been seen, somewhere slightly out of bounds”.

Inspired by his grandmother (“she’s 88 and still out there, even when it’s hailing”), Hart Dyke started gardening as a toddler. By five he had harvested his first carrots and by seven his teachers were used to him going missing for entire summer days. He once counted 63,424 orchids on a golf course.

He and Winder first met backpacking in Creel, Mexico, in late 1999. Hart Dyke was drying out native strawberry seeds when he spied Winder, who informed him of his plans to go to the Darién. Hart Dyke became excited — the mountains of Colombia were “dripping” with his favourite flower. “I might encounter the Dracula orchid or I might come across the twenty five species of the Stanhopea.”

They met in Panama City, as arranged, on March 6 and started trekking, conscious of the many warnings of dangers in the area. “But you have to push boundaries,” says Winder. “In retrospect, you could say our boisterousness, our attitude of ‘Oh, that is not going to happen to us’ caused our kidnapping.”

“It was in my mind, but things with chlorophyll were in my mind more,” Hart Dyke adds.

With two guides, they had been walking for seven days, dazzled by the vivid lushness of the jungle: the huge tree canopies, the lianas brushing the water, the flashes of red, green and blue of kingfishers and hummingbirds. Then two men materialised from the bushes. “We were sucking on lollipops, then suddenly I was being forced to the ground and looking down the barrel of an AK-47,” says Hart Dyke.

“Everything gave way,” remembers Winder. “You suddenly realise there is nothing you can do. Behind that rifle is a man with eyes and fingers. He’s really nervous about what he’s doing. He doesn’t know who we are and we don’t know who he is. There’s lots of shouting and, woomph, you fall to the floor.”

The pair were tied up (their guides disappeared) and walked back the way they came, terrified. “Paul’s face was so white,” Hart Dyke whispers.

“I saw the fear in Tom’s eyes,” Winder adds tonelessly. “He was almost looking through me rather than visualising me.”