Witnesses are being sought after a number of fires were started at a farm in Little Oakley, Corby.
The incident happened on Friday, August 10, between 2pm and 2.10pm, when a number of hay bales in various locations across the farm were set on fire, causing damage.
A spokesman for Northants Police said: “A 41-year-old man has been arrested in connections with this incident and released under investigation pending further enquiries.
“Officers are now appealing for witnesses who may have been in the area at the time or saw anyone acting suspiciously in the area.”
Witnesses or anyone with information can call police on 101 or Crimestoppers anonymously on 0800 555111.