French police have detained a man as part of investigations into a series of mystery horse mutilations across the country in recent months.
Police say the 50-year-old was arrested at his home in Alsace.
He is wanted in connection with an attack in Yonne, north-west of Dijon, last month.
Dozens of horses have been killed or maimed this year. The latest attack occurred south of Dijon on Sunday.
The owner called police at around 02:00 local time (01:00 BST) after seeing lamp lights in his meadow.
There were no serious injuries inflicted but in previous incidents animals have been left with their ears and genitals cut off.
Police do not know why the horses are being targeted. They also do not know whether it is the work of one person or if initial attacks have inspired copycat killings.
The suspect was detained on Monday morning in the town of Nambsheim, near the German border. Police have not released a name.
The prosecutor said the unemployed man was “known in Germany for attacking animals”.
An initial search at his home had not yielded any information, but “there is a lot of electronic material to sift through”, the prosecutor added.