Former pop star and now presenter Dieter Bohlen mercilessly teased the 69-year-old man when the footage was aired not long after his ill-fated holiday.
The Austrian man named only as Herbert P. was on holiday on the Maldives in November 2010 when RTL was filming its Deutschland sucht den Superstar (DSDS) "Recall" show there, the Express newspaper reported on Thursday.
The pensioner reportedly wandered into a restricted area of a swimming pool behind the judges' panel, and RTL aired the footage with a “humorous voiceover” and a horror film soundtrack.
"And now - gruesome, dangerous, ravenous - the monster from the deep," the voice said as Herbert P. was seen climbing out of the water.
Bohlen then added, "He looks like a beer bottle." Herbert P.'s identity was only masked by a black spot superimposed over his eyes.
Herbert P. said his life became traumatic after the incident, because people began ridiculing him. "Even my partner's boss talked to us about it," he told the Austrian Kurier newspaper. "And my cousin, who I have not heard from for a long time, called from Germany. Everyone was making fun of me."
He has since sought psychiatric help. "When I came back from holiday I was the happiest person," he said. "Then I couldn't sleep, I was awake every night, just because of this stupidity."
After Herbert P. complained, RTL paid him €9,000 compensation, a sum it described as "very generous" to the Kurier.
But the Austrian is now suing the broadcaster for a further €21,000. A court psychiatrist has already testified that the TV show caused psychiatric harm to Herbert.
RTL would not comment on the court case on the grounds that it was still ongoing.