FRANKFURT AM MAIN (AFP) - A nurse in Germany has been arrested on suspicion of poisoning five newborn babies with morphine, officials said on Thursday (Jan 30), adding that the infants had survived.

The woman was taken into custody on Wednesday after investigators found an oral syringe containing breast milk mixed with morphine in her locker at Ulm University Hospital in southern Germany.

The premature and newborn babies, who were between one day and five weeks old and staying in the same hospital room, suddenly all developed breathing problems "at almost the same time" in the early hours of Dec 20, said Ulm police chief Bernhard Weber.

"Only because of immediate action taken by the staff could the five lives be saved," he told a news conference.

Doctors do not expect the infants to suffer any lasting harm.

The nurse taken into custody has yet to be formally charged but faces five counts of attempted manslaughter and grievous bodily harm, Ulm prosecutor Christof Lehr told reporters.

The nurse denies poisoning the babies, he added.

'INCONSISTENCIES'

Ulm University Hospital initially suspected the infants had caught an infection.

But this was ruled out after urine tests came back negative on Jan 16, said the hospital's paediatrics chief, doctor Klaus-Michael Debatin.

The tests did however show traces of morphine - although none of them were supposed to receive the heavy painkiller, he added.

Morphine is administered to treat severe pain. In infants, it is also often used to treat withdrawal symptoms in babies born to drug-addicted mothers.

A morphine overdose can lead to life-threatening respiratory failure.

The hospital notified the police the following day, on Jan 17.

A search of the lockers of six employees on duty around the time of the incident turned up the syringe "filled with breast milk", said prosecutor Lehr.

Testing "confirmed the terrible suspicion that the syringe contained morphine", he added.

It is common for premature and newborn babies who are too weak to drink from a bottle to be fed orally through a syringe.

But the breast milk or formula they are given is never combined with medication, according to the hospital.

Prosecutors believe the nurse who was arrested acted with premeditation and "accepted that the babies could die" as a result of her actions, Lehr said.

The woman, only described as "young", has spoken to investigators in the presence of her lawyer but rejects the accusations against her.

Her psychological state is currently being evaluated.

"We have to assume that a crime was committed here," Debatin said.

The use of morphine is strictly regulated in Germany, he said, pointing out that the drug is stored in "a locked cupboard" and a log is kept of when it is administered and on which patients.

The hospital has however "found some inconsistencies" in the data, Debatin said.

SIMILAR CASE

Ulm University Hospital said in a statement that "rapid medical intervention" meant the babies' conditions "were stable again within 48 hours and they could breathe on their own again".

The institute's medical director, doctor Udo Kaisers, offered the hospital's "sincere apologies" for the incident and vowed to "work hard" to restore the public's trust.

"We can very much understand the worries and fears of the affected parents," he said.

"Our employees too are shaken."

The incident revived memories of Niels Hoegel, a German nurse jailed for life last year for the murder of 85 patients.

Hoegel, believed to be Germany's most prolific serial killer, murdered patients with lethal injections between 2000 and 2005, before he was caught in the act.

He admitted to administering the injections that caused heart failure or circulatory collapse so he could then try to revive patients to impress colleagues.

The drama in Ulm also carried echoes of case in a hospital in the central city of Marburg, where a nurse was found guilty of endangering the lives of three premature baby girls in 2015-2016 by unnecessarily giving them sedatives and anaesthetics.

The woman was handed a life term in November 2019.

Prosecutors said she was motivated by a desire to show off her life-saving medical skills.