He and two friends managed to tiptoe past a row of minefields, but they triggered fire from an automatic spring gun. One of Seiptius' crew died, and their cover was blown.

They were quickly arrested by border guards. But records kept by East Germany's notorious secret police, known as the Stasi, show Seiptius as having died during that botched escape attempt.

"I've been alive for the past 48 years," he said.

Eventually his name found its way to a list compiled by a museum in Berlin of all the people who died along Germany's East-West border.

It was only the second case of an incorrect entry to have surfaced in the past half a century, said Alexandra Hildebrandt, the director of the Haus am Checkpoint Charlie museum, which keeps the tally of border victims.

The other case came to light more than two decades ago.

Hildebrandt said that although her organisation spent months researching individual entries - even examining autopsy reports in some cases - the list was still a "work in progress".

"It's not always that easy to get access to this information," she said. "Former employees of the secret police still control a lot of it."

Seiptius tried two more times, unsuccessfully, to escape East Germany until he was granted permission to leave. Today, he lives near the western German city of Mainz.

The case was not made public until recently, when Seiptius' ex-wife stumbled across an article on the website of the German broadcaster NDR, which listed Seiptius as deceased.

"It was pure coincidence," said Patricia Seiptius. "I was looking for something online and one of the search results was this article, I looked at it and there was his name. "I couldn't believe it."