The man is likely to face criminal charges for breaching aviation safety and explosives laws, and will have to pay for the cost of the police operation. It was unclear whether the operators of Munich airport, Germany's second biggest, will also sue the man for damages, DPA reported.
War souvenirs are still readily found in parts of the country and few hikers are aware of the risk the rusty pieces of metal still pose.
Across the Austrian Border, in Carinthia state, a hiker was killed after coming across an unexploded shell on Lake Ossiach.
On Friday a police spokesperson confirmed that the tourist was handling old ammunition which had exploded, killing him. It is believed to have been an unspent Second World War shell.
The lake was used to dispose of unused ammunition at the end of war 75 years ago.
A police spokesperson told Associated Press the lake poses little risk to swimmers and hikers, providing they leave the objects well alone. In particular, shells should not be taken as souvenirs.
- With Associated Press