Iranian authorities have released five British sailors who were detained on November 25, the ISNA news agency said on Wednesday.
"The British nationals were released after an inquiry showed that their illegal entry was unintentional," the agency said.
The BBC said the Foreign Office was investigating the report.
The yacht, the Kingdom of Bahrain, is believed to have mistakenly strayed into Iranian waters last Wednesday as it sailed from Bahrain to Dubai for the Dubai-Muscat Offshore Sailing Race.
A spokesman for the Sail Bahrain, the vessel's owner, told CNN that a malfunction in the propeller might have caused the yacht to drift into Iranian waters.
MOSCOW, December 2 (RIA Novosti)