The probe extends to DNV and four other West European members of the International Association of Classification Societies (IACS), Lloyd's Register, Germanischer Lloyd, France's Bureau Veritas and Italy's RINA, DNV spokesman Tore Hoeifoedt said.
Inspectors from the European Surveillance Authority (ESA) arrived at the headquarters of Den Norske Veritas (DNV) on Tuesday and continued to work yesterday, Mr Hoeifoedt said. He denied any wrongdoing and said the substance of the probe remained unclear to DNV.
'The (European) Commission has been informed that there might be breaches of the competition law,' he told Reuters. 'It is orchestrated in five countries,' Mr Hoeifoedt added.
ESA monitors non-EU member Norway's compliance with European regulations under the European Economic Area (EEA) treaty.
In the EU members, the raid was carried out by the European Union's competition watchdog, Mr Hoeifoedt said.
'We don't know the substance of that information, so we are surprised and we don't understand the basis of the inspection,' Mr Hoeifoedt said. 'But of course we are cooperating fully with the teams and giving them what they want. 'At this point, we are eager to know more about the information triggering the action,' he added.
Mr Hoeifoedt said that the suspicions appeared to be related to IACS members' way of behaving towards non-members of the sector organisation, which has 10 members altogether and accounts for 80 per cent of classification of the world fleet.
Vessels need a classification to be allowed to put into port, and ship owners buy them from the classification societies which inspect ships during construction.
Asked if IACS members colluded in an anti-competitive manner, Mr Hoeifoedt said: 'No, of course we do not perceive it that way.
'And that is why it is important to find out what claims have been made and how someone perceives the organisation to be breaking the rules.' He declined to speculate on the source of the claims made. DNV says it has 16 per cent of the world fleet under its classification.
In addition to the five West European members, the IACS's other members are the American Bureau of Shipping (ABS), the China Classification Society (CCS), the Korean Register (KR), Japan's Nippon Kaiji Kyokai and the Russian Maritime Register of Shipping.