Pretty much everyone knew but OTOH it's not like they were making contracts with prisons, they had contracts with ordinary GDR companies which used prison labour to supplement their own workforce, often on an irregular basis. E.g. if you had a contract with a GDR company to supply a certain number of t-shirts per month for three years, they'd do it with their own workforce, they'd get another short-term contract and fulfil part of that and part of your contract with prison labour. The whole economy was infested with it, basically impossible to do business with the GDR and not have prison labour involved somewhere in the supply chain. What are you expecting, you're doing business with tankies.

I'd see stronger culpability if they had been contracting out dangerous work. GDR wasn't stellar at work safety in general, not atrocious either, but prison labour in e.g. the chemical industry? It's not that they didn't gave a fuck, it was extra unsafe by design.

Of course they knew. For Ingvar Kamprad, it was all about saving money. No matter what.

I am sure Ikea will acknowledge having contributed to illegal deforestation of original forests in Romania, Belarus, and Russia in the 2020s at some point, too.

Because they are currently the only company acknowledging their fault? Boycotting them while ignoring all the other companies benefiting from the exact same practice seems counterproductive…

This is in no way a defense, but rather an accusation: many other companies pull or have pulled similar things. Hasbro famously used near slave labor when they partnered with Good Shepherd Sisters, one of many similar "Magdalene Laundries"; religious convents that some women were put in for sins as horrifying as "having a baby out of wedlock."

Behind the Bastards discusses them in their episodes titled "How the catholic church murdered Ireland's babies"

So prison labor for profit is bad now?

It should be a matter of course, but the EU already banned forced labour explicitly this years. The question is rather that we must ensure that the law is enforced.