Police in Gibraltar are questioning the captain and "first mate" of the seized VLCC Grace 1 that is suspected of breaching sanctions against Syria and Iran.

The UK territory's chief minister Fabian Picardo said in a statement to parliament that police arrested both men from the 301,000-dwt Ukrainian-owned ship (built 1997) on Thursday.

This followed a protracted search of the vessel during which documents and electronic devices were seized and examined.