ROME, Aug 2 (Reuters) - An EU naval mission led ​by Italy boarded a tanker from Russia's so-called "shadow fleet" on Sunday, the second ‌such operation in less than two weeks as Europe intensifies scrutiny of vessels suspected of helping Moscow circumvent oil sanctions.

Italy's Defence Ministry said the Toa Payoh, a tanker subject to EU sanctions, was intercepted ​west of the Sicilian island of Pantelleria while sailing from Benin to Istanbul.

The ​vessel had switched to a Cameroon registry only last week, according to ⁠a source familiar with the operation. Maritime authorities launched the inspection to verify that ​the tanker was legally entitled to fly the Cameroon flag and that its registration documents ​were valid.

The source said the EU naval mission, named operation EUNAVFOR MED Irini, did not have the authority to seize vessels during such inspections, meaning the Toa Payoh was not detained.

However, documentation gathered during ​the boarding was still being examined and could be used by national authorities for ​a subsequent sequestration if necessary.

The Toa Payoh's captain initially failed to cooperate with the EU mission, prompting ‌a team ⁠of Italian military personnel to board the vessel from a helicopter launched by the Thaon di Revel, the EU's EUNAVFOR MED's flagship.

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.

There was no ⁠immediate comment from Russia.

Sunday's operation follows the July 20 boarding of the MV South Star, another tanker linked to Russia's shadow fleet that ​was inspected by Irini forces over suspicions it was sailing also ​under a ⁠false flag.

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 U.N. arms embargo on Libya. EU governments have since broadened its scope, authorising ​it to conduct verification boardings.