Iran has secured the release of a container ship seized by authorities in Hong Kong more than three months ago due to sanctions-related problems, the semi-official Fars news agency reported.

Five vessels operated by the Islamic Republic of Iran Shipping Lines (IRISL) were impounded at ports around the world late last year as sanctions on Iran caused European banks to call in loans they had made to IRISL early.

Three ships held in Singapore were released in January. One is still impounded in Malta.

The chairman of the state-owned shipping line, Mohammad Hossein Dajmar, said the loan, from an unidentified German bank, would be repaid and the ship released after more than 100 days in Hong Kong.

"Measures taken for loan settlement with the European bank neutralised the international plot to stop Iran's national shipping line," Dajmar told Fars.

The shipping problems are one symptom of the sanctions which were tightened last year to make it more difficult for Iranian companies to access international banking services. The measures are aimed at forcing Tehran to curb its nuclear program which many countries fear could be aimed at making weapons, something Tehran denies. (Reuters)