An EU mission led by Italy boarded a tanker belonging to Russia's so-called "shadow fleet" on Sunday to verify its nationality and flag registration, Italy's Defense Ministry said.
It was not immediately clear whether the vessel had been detained while the checks were carried out.
The ministry said the Toa Payoh, a tanker under EU sanctions that was sailing under the flag of Cameroon, had been intercepted in the Mediterranean, west of the Italian island of Pantelleria, while travelling from Benin to Istanbul.
The ship's captain initially failed to cooperate, prompting a team of Italian military personnel to board the vessel from a helicopter launched by the Thaon di Revel, flagship of the EU's EUNAVFOR MED Irini operation.
The inspection, carried out with the support of a Greek vessel and a Polish maritime patrol aircraft, lasted about two hours and was completed safely, the ministry said.
Italian authorities were examining documentation obtained during the inspection.
The European Union has imposed sanctions on scores of vessels that it says form part of a "shadow fleet" used by Russia to circumvent restrictions on its oil exports since its invasion of Ukraine.
EUNAVFOR MED Irini is an EU naval mission launched in 2020 to enforce a UN arms embargo on Libya. EU governments have since broadened its scope, authorizing it to conduct verification boardings of vessels suspected of sailing under false flags.
