The Frankfurt Public Prosecutor's Office confirmed on Friday that it is investigating a captain in Germany's Bundeswehr army for violating the military weapons control act as well as for the "unauthorized handling of radioactive material."

The confirmation came after the publication on Friday of a report in the German weekly magazine Der Spiegel that was sourced from Defense Ministry documents.

Search warrant issued after package intercepted at Frankfurt airport

A Bundeswehr munitions analyst specialized in improvised explosive devices (IEDs), the 32-year-old came to authorities' attention when customs agents at Frankfurt International Airport discovered a package of sound suppressors, or silencers, that the man had attempted to mail to an individual in the US — where it is illegal to possess silencers not properly registered as required by the National Firearms Act. 

That find prompted police to obtain a search warrant for the man's residence. He was arrested during an October 12 raid in Aldenhoven, a town of some 14,000 in the western state of North Rhine-Westphalia. The man remains in police custody.

During the raid, police found a cache of illegal weapons including AK-47 assault rifles, anti-tank and anti-aircraft weapons, as well as grenades.

Authorities confirmed that they also secured an "unspecified quantity" of Strontium-90, a radioactive isotope found that is used in both medical and industrial applications as well as in nuclear weapons.

Germany's Defense Ministry said the weapons do not belong to the Bundeswehr. The Spiegel report cited sources saying the weapons likely came from former Soviet bloc depots.

Further, the discovery of BND foreign intelligence agency documents on North Korea has prompted the Bundeswehr's Military Counterintelligence Service (MAD) to join the investigation.

Latest in a string of shocking Bundeswehr incidents

The report Friday marks the latest in a series of startling revelations involving current and former military personnel in Germany.

On Wednesday, police in southern Germany arrested two former soldiers "strongly suspected" of having attempted to form a paramilitary group of 100-to-150 mercenaries — made up of other former soldiers or police officers — to fight in Yemen's civil war.

Earlier this month, the Bundeswehr suspended "several dozen" soldiers in its ceremonial guard on suspicion of committing sexually aggressive acts and having far-right extremist sympathies.

In May, a Bundeswehr soldier who allegedly planned to attack prominent politicians while posing as a Syrian refugee, went on trial.

In 2020, the Bundeswehr's elite Special Commando Force (KSK) was partially disbanded after a scandal in which munitions were stolen and members openly displayed far-right extremist paraphernalia and behavior.  

js/sms (AP, dpa)