If it wasn't for their metal seals stamped with the letters "MFS", the innocuous-looking, airtight preserving jars displayed in the dilapidated building on east Berlin's Ruschestrasse might be mistaken for bits of retro kitchen equipment. Yet their purpose was once far more sinister.
They still contain the patches of fabric that were used by former East Germany's hated Stasi secret police to catch opponents of the regime.
Anyone who has seen the award-winning film, The Lives of Others, will recall how Stasi dogs tracked down anti-communists after having their noses rubbed with cloths impregnated with a suspect's sweat.
Next to the jar display are detailed instructions on how to use the so-called "smell cloths". A diagram shows a special Stasi chair containing a false bottom on which the cloths were placed without the suspect noticing.
"The subject must remain sitting for at least 10 minutes if a reliable sample is to be obtained," the accompanying Stasi manual states blandly.
The letters on the jars' metal seals stand for "Ministry For State Security" – the official name for the Stasi.
The exhibits are among hundreds of secret police relics, ranging from tiny spying cameras and bugging microphones to a snack bar used by Stasi officers during their breaks from surveillance, which stand as if frozen in time in Berlin's former Stasi headquarters.
Yet the mammoth 1.1 million square foot former secret police complex, turned into Germany's main Stasi museum in the months that followed the fall of the Berlin Wall, is at the centre of an acrimonious dispute over how best to remember the country's divided past.
The row involves Chancellor Angela Merkel's conservative-liberal government, city planners and the erstwhile opponents of East Germany's Communist regime.
The German government, which has been criticised for failing to adequately address the country's history prior to reunification in 1990, wants to take over the building and turn it into a national memorial.
The local Berlin borough, which is sick of its reputation for being the home of one of the nastiest secret police forces in history, would like to see the entire complex demolished.
Yet the former East German dissidents who have been running Berlin's Stasi museum for the past two decades fear both options so much that they have defied government orders to vacate the premises and are now squatting in the building and refusing to budge.
"Obviously, we don't want to see our museum demolished," said Jörg Drieselmann, a former East German dissident who is the museum's director. "Neither do we want to be taken over by the government. We are afraid that they will sanitise the place and destroy the authenticity that makes Berlin's Stasi museum unique," he told The Independent. "We were supposed to get out on 31 May, but nobody has come to evict us so far. Effectively, we are squatters," he added.
As a result, all government funding for the museum has been cancelled since the beginning of June. Mr Drieselmann, 53, was jailed in East Germany when he was a teenager. The Stasi incarcerated him in one of their interrogation prisons in the city of Erfurt for opposing the regime.
He subsequently left the country after the then West German government paid for his freedom. In January 1990, six weeks after the Berlin Wall fell, he was among a group of regime critics who stormed Berlin's Stasi HQ and occupied the building in order to stop the secret police destroying their files.
The regime's critics formed an organisation called Anti-Stalinist Action, which has been running Berlin's Stasi museum in the former secret police headquarters ever since. Mr Drieselmann is an expert on the Stasi and was chief historical adviser during the making of Florian Henckel von Donnersmarck's film, The Lives of Others.
"I had to re-write most of the script to make the actors speak like real Stasi officers," he joked last week. Along with his former dissident colleagues, he is appalled at the idea of the museum being taken over by the government.
"It will be another example of the west taking over the east," he insists.
There can be no disputing Mr Drieselmann's boast that his Stasi museum is authentic. Its centrepiece is a long, wood-panelled corridor with offices leading off it on the first floor of the main 1960s building.
It was once the nerve centre of a secret police state in which more than 280,000 of East Germany's 16 million inhabitants worked as Stasi officers or secret police informers.
The first floor contained the offices of Comrade Erich Mielke, the reviled Stasi chief who ran the organisation with Stalinist dedication until the bitter end.
The floor was used as a location in the filming of The Lives of Others. Its exhibits include Mielke's special emergency phone, which enabled him to talk instantly with other Warsaw Pact secret police chiefs.
Its centrepiece is the original Stasi conference room complete with an oil painting by Wolfgang Frankenstein, Mielke's favourite artist.
The picture depicts heroic East German militiamen comforting a group of young women workers while in the background their comrades build Berlin's "anti-fascist protection barrier" – Stasi speak for the Berlin Wall.
Mr Drieselmann says he fears that all this could be lost if the Ministry of Culture goes ahead with its plans to take over the building. The ministry wants to modernise the complex and install the kind of computerised "interactive" elements that are a feature of museums across the globe.
Helge Heidemeyer heads the government agency that has been given the job of revamping the museum. He points out that private individuals have a virtual monopoly on recent German history as most of the Berlin museums dealing with the former East Germany are in private hands.
He argues that there is a pressing need for an official, state-run museum to redress the public-private balance and says his office is more than ready to collaborate with Anti-Stalinist Action. "It would be an ideal opportunity," he insists.
However, Mr Drieselmann says that his museum already attracts more than 100,000 visitors a year who pay an entrance fee of €4 (£3.30) each. He spends much of his time conducting classes of schoolchildren around the building and playing Stasi-dissident role games with them to increase their understanding of what East Germany was really like.
"We don't need interactive elements," he insists.
The uncertainty hanging over Berlin's Stasi museum has been compounded by local politicians in the city's Lichtenberg borough. They are fed up with the district's sinister reputation thanks to the secret police, one which has proved as difficult to shed as an indelible stain.
Andreas Geisel, a local Social Democrat party councillor, stresses that the complex is not limited to the Stasi museum. It includes 32 other large and ugly concrete blocks that once contained offices, a travel bureau, a supermarket and cafeterias for the 7,000 Stasi employees who worked in it. Mr Geisel would like the complex to be declared a redevelopment area and would be quite happy to see it razed to the ground. "A city needs to continue to develop," he says.
Yet Mielke's grim headquarters are likely to remain a grim memorial to the paranoid police state that was once East Germany.
The building has been declared an historic monument and cannot simply be demolished. The question is, in what form will it survive?
Germany's Culture Ministry says it hopes to reach a compromise with the ex-dissidents now occupying the museum.
But Mr Drieselmann is content to squat. "We've done our sums. We attract enough visitors to be able to survive without the state," he insists.
Erich Mielke: From murderer to Minister of State Security
"But I love everyone" were the last words spoken in public by Erich Mielke, the reviled Stasi chief who ran one of Europe's most pervasive secret police networks for more than 30 years. When he made this remark to the East German parliament four days after the fall of the Berlin Wall in 1989, the man who was feared and hated for most of his career was laughed out of the chamber.
Mielke was born in 1907 and joined Germany's Communist Party at 20. In 1931, he fled to the Soviet Union after shooting dead two policemen during a political street battle in Berlin. In Moscow, Mielke was trained in secret police tactics. He fought with German communists during the Spanish Civil War and went underground in France during the Second World War, briefly doing construction work for the Nazis. By 1945 he was in the Soviet-occupied zone of Germany and helping to set up a fledgling security service, which later became the Stasi. Mielke reigned as Stasi chief from 1957 until the Wall fell in 1989. At the height of his power in the early 1980s, his ministry employed 91,000 secret police and 190,000 informants.
Mielke was arrested in 1990 and three years later was sentenced to six years in jail for the 1931 murders. However, he was freed 17 months later on health grounds. He died aged 92 in 2000 and is buried alongside other top-ranking East German Communists in eastern Berlin.
Mielke was never tried in the reunified Germany for crimes he committed while Stasi chief, or for his role in supporting the building of the Berlin Wall.