BERLIN (AP) — A nurse has been arrested in Germany on suspicion of attempted murder following allegations that he gave three patients overdoses of drugs they weren't supposed to receive in hopes of heroically rescuing them, authorities said Wednesday.

The 24-year-old man was arrested on Monday, German news agency dpa reported. The alleged crimes took place at a Munich university hospital at the end of October and on Saturday, and all three patients survived, authorities said.

The nurse, whose name wasn’t released in line with German privacy rules, is being investigated on suspicion of three counts of attempted murder, Munich prosecutor Anne Leiding said.

The nurse denied the accusations. He had worked at the Klinikum rechts der Isar hospital since July via a temporary employment agency. Police said they would check for any further possible victims or irregularies from the time he worked there.

The hospital said that the condition of two patients worsened unexpectedly on Saturday, and an examination led to suspicions they were given a medicine they shouldn't have been. Similar suspicions arose in the case of a third patient.

The nurse involved was suspended from duty immediately and police were contacted, the hospital said. One of the three patients is still in a “serious but stable” condition. The other two are considered out of danger, dpa reported.

Investigators wouldn't say what substance was found in the patients' blood.

The Munich prosecutor said online chats suggested that the nurse wanted to distinguish himself with resuscitation efforts. She would not say with whom he had the chats, dpa reported.

The allegations are reminiscent of a case in northern Germany, where a former nurse, Niels Hoegel, was convicted of murder last year and sentenced to life in prison for killing 85 patients by deliberately bringing about cardiac arrests.

Hoegel injected patients with overdoses of heart medication and other drugs because he enjoyed the feeling of being able to resuscitate them, authorities said. His conviction last year came on top of a previous one for two murders. He is believed to be modern Germany's most prolific serial killer.