The former head of a mushroom company in Limburg should be jailed for 4.5 years for fraud, forgery and human trafficking involving 600 Polish workers, the public prosecution department said on Thursday.

Geert V, former director of Prime Champ Production, the company’s financial chief and three Polish managers should all be jailed for their roles in exploiting the workforce over a period of years, the court was told.

The workforce, made up of Polish women, were systematically underpaid and overworked, generating an extra €6m for the company, news agency ANP said.

They also had to hand back part of their wages for living expenses. However, they lived in extremely poor conditions, with often only cold showers, and were given bad food, the prosecutor alleges.

The investigation into Prime Champ dates back to at least 2012.  The company went bankrupt in 2013 following the allegations and was taken over by Ireland’s Monaghan Mushrooms.