An 84-year-old man is accused of using a gun to force a 77-year-old woman to have sex with him in the city of Emden in the north of the country.
The local public prosecutor and police force said on Thursday that several weapons with ammunition were discovered during a search of the man’s flat in the village of Krummhoern on Wednesday.
A police officer confiscated the man’s gun licence.
The prosecutor and police said the man is believed to have carried other attacks since November 2016.
An investigation is ongoing.