The false warning spoiled a business trip to the U.S. for the man's son-in-law, who was stopped at a Florida airport and questioned for 11 hours before being sent back on a plane to Sweden, the Sydsvenska Dagbladet daily reported.
U.S. authorities apparently reacted to an e-mail sent to the FBI saying the man "likely has links to the Muslim terror organization al-Qaida's network in Sweden," the newspaper reported.
The 52-year-old father-in-law admitted to having sent the e-mail after it was traced to his home computer, the paper said. He reportedly told police he sent the e-mail in anger after a dispute with his son-in-law, who was divorcing his daughter.
The man said he did not expect such a "paranoid reaction" from U.S. authorities, Sydsvenska Dagbladet reported.
According to court documents, he was charged Thursday with grave defamation in the district court in Lund, southern Sweden, and could face up to two years in prison if convicted.