"They are psychopaths," said Paul Quirin, head of the Arbeiterwohlfahrt (Awo) charity, which runs the care home in Spiesen-Elversberg, near Saarbrücken in western Germany, at a press conference on Tuesday.
"We apologise for what occurred. Something like this simply must not happen," he continued, promising a thorough investigation.
Two patients are thought to have died as a result of abuse they suffered at the hands of the two men - a 25-year-old employee and a 35-year-old carer who worked in the home's intensive care unit, the Saarbrücken Zeitung reported on Wednesday.
The two men are accused of torturing and humiliating as many as 32 patients in the past few months. Ten co-workers, who said they had been intimidated into not speaking out earlier, eventually reported the abuse. On Monday, Awo alerted state prosecutors, who have launched an investigation on suspicion of bodily harm leading to death.
Awo has also hired lawyer Klaus John to initiate its own suit against the two men.
John said at the press conference that the 35-year-old suspect had carried out a surgical procedure on a dying woman in the intensive care section – without anaesthetic. Confessing to the crime, the carer reportedly claimed he could do it better than any surgeon.
John described the incident as a case of "profound sadism." The 35-year-old carer, who had only been working at the home since September, is also accused of killing a patient with an overdose of morphine.
The younger carer, who has been working at the home since 2005, is said to have removed a patient's oxygen tube and asked him how he liked not having any air. He is also accused of deliberately cutting a patient because he wouldn't keep still while being shaved.
The two carers also apparently stole anaesthetic drugs for their own use. In addition to the drugs, two gold watches apparently belonging to patients were discovered in one of the men's lockers.