The group, consisting of an estimated thirty people, is headed by a 45-year-old father of two, Expressen reports.
The unmarried former managing director is also moderator of a large internet animal sex forum and has a number of dogs and horses on his farm in southern Sweden.
Having infiltrated the network over a period of several months, Expressen eventually confronted the 45-year-old over his alleged mistreatment of animals.
But the man was quick to defend his relations with a bitch he bought online from a city-dwelling family who said they wanted the dog to have a better life in the countryside.
"Any of the times I did anything with her she was the one who backed into me and provoked it. She was in heat and made herself available. There were also times later when she didn't want to and then I backed out immediately," he told Expressen.
During the time spent with members of the network, Expressen learned that the group regularly brought along a range of different animals to "sex meetings" at rented premises.
There, members of the group filmed their sexual encounters and distributed them to other animal sex enthusiasts.
At one meeting in a small village in Småland, five men waited for a woman who had promised to bring along two dogs. But when she was unable to make it to the meeting, the men spoke instead of their experiences, including a previous visit to a colleague they referred to as "donkey man".
"He has a goat and a couple of donkeys. We tried with a donkey but it didn't work. But we did have sex with the goat," one of the men told Expressen.
Previous calls for a law banning sex with animals have fallen on deaf ears. Agriculture Minister Eskil Erlandsson outraged many observers earlier this year with a graphic defence of existing animal abuse laws, in which he presented examples of the difficulties faced by courts when trying to differentiate affection from abuse.
"Is it, and should it be, legal to spread something on the genitalia that might smell or taste nice to a dog, in order to allow the dog to lick off whatever is spread on the genitalia?
"Should it be permitted to stroke a bitch's teats with love, or should it be classified as animal sexual abuse?" the minister wondered.
According to the Swedish Animal Welfare Agency, 115 cases of bestiality were reported in the years 2000 to 2005.
Despite indications that many of the animals had sustained injuries, none of the reports led to criminal charges.
See also: Agriculture Minister Eskil Erlandsson's controversial comments (in Swedish)