The note, written in pencil then rolled up and inserted in a bottle, contains the names of seven young people who probably thought they were doomed to die in the notorious Auschwitz death camp.
A construction crew renovating a cellar near the Auschwitz site discovered the bottle hidden in a concrete wall, officials said on Monday.
Dated September 9, 1944, the note bears the names, camp numbers and hometowns of the seven prisoners -- six from Poland and one from France. "All of them are between the ages of 18 and 20," the final sentence reads.
"They were young people who were trying to leave some trace of their existence behind them," said Auschwitz museum spokesman Jaroslaw Mensfelt. He said two of the prisoners survived the camp but he did not have further details.
Workmen were tearing out a wall in the basement of a college building in the town of Oswiecim which was called Auschwitz by the Nazis during World War II on April 20 when they discovered the bottle, college spokeswoman Monika Bartosz said.
She said the note appeared to have been written on a scrap from a cement bag. Museum experts have verified the authenticity of the note, which will be handed over to the museum in early May.