Five adult dogs and 25 puppies were stuffed in the freezer, The Copenhagen Post reported Tuesday.
"There were adults, younger dogs and puppies," Soren Bach, the vice police commissioner in Hjorring, said.
Police also confiscated four live dogs, four sabers and four bayonets, the Post reported.
The 66-year old man, whose name wasn't released, has been previously convicted of breaking dog laws. Authorities have reportedly been dealing with the man for three years, since neighbors filed complaints about barking dogs.
In April, authorities deemed him unfit to have dogs on his property, the Post reported.
When police learned that he was violating the ban, they searched the property and found the dead dogs.
"It is unusual to keep so many dogs in a freezer, so we need to investigate, via an autopsy, how the dogs have been put down," Bach said.