For 35 years, the museum, a house which used to be within touching distance of the Berlin Wall, has been a shrine to humanity's yearning for freedom, evidenced by the numerous breath-taking escapes it chronicles. The people of the "Zone" came on foot, in canoes, crawled through tunnels and soared above the Wall in a variety of ingenious contraptions. More often than not, Rainer Hildebrandt, the museum's founder, was there to welcome and assist them.
The old freedom-fighter who has written a book about non-violent resistance to tyranny is still in charge, but now, at the age of 84, he is being cast in the role of the tyrant, accused of taking liberties with his employees' basic rights.
Mr Hildebrandt's museum is torn by a vicious dispute, its name sullied by unspeakable accusations. Some of the staff - dissidents of old almost every one - claim to have fallen victim to a purge. As an iron curtain descends in the workplace, the oppressed are fighting back with the only weapon known to them: the samizdat.
At the end of last month seven sacked employees wrote an open letter to Berlin's regional parliament, complaining of "fear and loathing" at the House at Checkpoint Charlie. In just over a year, they claimed, 12 museum workers had been driven out by methods ranging from "psychological terror", to "threats of violence".
There has indeed been an impressive recent turnover of staff, but Mr Hildebrandt says many of those dismissed had been caught on video with their hands in the till. The taped evidence of the alleged thieving conspiracy have been sent to prosecutors in Berlin, and charges are being pressed.
But accusations are flying in both directions. According to the rebels, the alleged pilfering is merely a pretext for getting rid of troublemakers. One of the sacked dozen, for instance, had fallen through the metaphorical trapdoor after letting it be known that chunks allegedly from the Wall on sale at the museum had been salvaged from an ordinary skip, and not from the dustheap of history. Two of the workers charged with theft have struck back with libel writs.
Another victim of the purge was a member of the enterprise council, which under German law holds the balance between staff and management. As a result of this person's departure, the council is now inquorate, and Mr Hildebrandt enjoys absolute power over his minions. There was also an association watching over the museum, but in a sudden escalation of the cold war at Checkpoint Charlie, Mr Hildebrandt got rid of the last dissenter on this body earlier this month. The latest victim is Wolfgang Templin, a well-known civil rights activist from the Communist era, who at one time was regarded as Mr Hildebrandt's heir apparent.
But that was before the patriarch married Alexandra, a Ukrainian woman nearly 50 years his junior. Three years ago, Mrs Hildebrandt was brought into the management, and the family atmosphere carefully nurtured over the previous three decades turned suddenly sour. The staff resented the new boss, and especially her methods.
"She has no idea how to deal with employees in Germany," Mr Templin says. "She barks orders, pesters people with telephone calls at 6 o'clock in the morning." Mr Templin quit "the feudal regime" in 1996, but clung to his seat on the association's board. Just over a week ago he was summoned to a meeting, where he was accused of bringing the museum into disrepute. His crime: casting doubt on the video-taped evidence of theft.
According to Mrs Hildebrandt, the dispute has been blown out of all proportion by the press, and it remains a criminal matter. Asked to comment on allegations about her management style, she referred the Independent on Sunday to the prosecutor's office. But she has said before that she wants to run the place, which attracts nearly 400,000 visitors every year, in accordance with "business principles". The museum is a charity supported by lottery money.
The people still lucky to have a job at the House at Checkpoint Charlie say they are not allowed to speak about the conflict. "Everything you read in the papers is true," declares one, on condition of anonymity. Hope is in short supply. The old guard is digging escape tunnels, again.