Tensions between Sweden and the German company Thyssen Krupp Marine Systems (TKMS) took a surprising turn last Tuesday when the Swedish Defence Materiel Administration carried out a raid on the Malmö shipyard belonging to Kockums, Thyssen Krupp's Swedish subsidiary.
The decisive move has left military experts baffled, with one claiming he has never seen anything like it.
"This is very strange, very unusual," Gunnar Hult, a professor at Sweden's National Defence College, told The Local on Tuesday.
The operation spoke volumes about the "magnitude of the conflict" between the Swedish state and the shipyard owners, he said, adding he was amazed the implications were never properly examined in the Swedish press.
Indeed, details of the reported raid by the defence administration (Försvarets materielverk - FMV) are few and far between.
"In front of several witnesses and with the protection of the military, FMV security came to Malmö and let themselves into the lab to take sensitive technological equipment," reported Sveriges Television (SVT) on Friday.
An FMV spokesperson described the incident as "a routine transportation of defence material"
"Because of the fact that it was a transfer of defence material, belonging to FMV, all information regarding the transfer is classified as secret," the spokesperson said.
Hult, who specializes in military technology at the defence college, assumed that the military was looking for drawings or design details, potentially about the Stirling engine.
He explained that some parts of Kockums' design belong to the Swedish military. Those designs were then rented to contractors, but with the ownership structure up in the air the military might have felt compelled to confiscate certain items.
"The kind of things they install into the web platforms. Encrypted," he explained. "This is pretty classified stuff."
FMV confirmed that the A26 submarine model is owned in full by the Swedish state.
Hult added that the actions of the FMV, which is tasked with delivering defence logistics to Sweden's Armed Forces (Försvarsmakten), were legally murky.
"I suppose if they say it refers to state interests then they'll be able to get away with it," he said.
"And with a neighbour to the east that we've never really trusted, we've developed our own submarines rather than buying them," he explained.
That changed when the Soviet Union imploded.
"There was less interest in the sea and in submarines. They allowed the Germans to buy a Swedish company," he said.
Current affairs, however, may have changed the game, as Swedish distrust of Moscow risks flaring up again.
"With what's happening in Ukraine, there is a renewed interest in submarines," Hult said.
That could have set the stage for the raid, and what was to come next - Swedish military technology makers Saab announcing a memorandum of understanding with Thyssen Krupp to take over the Kockums shipyards that the Germans have owned for 15 years.
Saab fits neatly into the picture because the Swedish government has long underscored the importance of having domestic shipbuilding programmes.
An FMV spokesperson said the agency took "a positive view" of news that Saab had signed an MOU, with the viability study set to be completed in June. Kockums employs around 900 staff in Sweden, and as part of the agreement, the Swedes have agreed to stop poaching staff from the Germans, a Saab spokesman said.
Hult explained that Saab was the only choice to take over.
"There is no one else. Saab has naval experience. They haven't made submarines but they have made sonar systems and torpedoes... a lot of things that are part of submarines. They were the only choice to take over."
Hult added that he was "surprised" the Germans were willing to negotiate with Saab, as a sale would turn Saab into a significant competitor to Thyssen Krupp's Kiel-based submarine production.
"And I wouldn't be surprised if there were a lot of phone calls between the Swedish and German governments about this," Hult told The Local. "Especially as it's such an important strategic affair."