The men were arrested in March and were held in jail for stealing $138,152 in cash and jewelry from elderly people in northern and eastern Sweden, The Local reported.
"They have been very cunning and have played on weak points," said Mikael Hedstrom of the Gavle police.
Police say the men researched their victims before conning them.
"They'd done their homework. If the woman had a grandchild called Kristoffer, then the caller would ring and said 'Hi Grandma, it's Kristoffer,'" Hedstrom said.
Police believe the suspects conned up to 150 people.
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