Police said the investigation, which is connected to investigations in Finland and Britain, resulted in a raid on the Harnosand house, where the rare eggs were hidden beneath a trap door, The Local.se reported Tuesday.
Investigator Stig Anddersson said the men are believed to be connected to a Finnish man arrested in June with 10,000 rare eggs and a British suspect who allegedly sent a warning email to one of the Swedish suspects after his arrest.
"There are different forums on the Internet that connect these people," Anddersson said.
The men are accused of taking the eggs -- which include owls, eagles, chickadees, nightingales, cranes and plovers -- from across the country. They are accused of aggravated hunting crimes and breaching protected species laws.
The men could each face up to a year in prison if convicted.
Police said egg thieves are known to build collections and trade with other collectors.