BRUSSELS, Belgium (AP) -- European Union regulators opened a formal investigation Monday into suspicions that French pharmaceutical giant Sanofi-Aventis illegally obstructed EU inspectors who raided the company's headquarters during an antitrust probe.
In a statement, the European Commission, the EU's executive branch, said company officials refused to allow EU inspectors examine and copy documents until French authorities produced a national search warrant during the raid in January.
The Commission said the EU treaty empowers its officials to search company records and take copies of documents during unannounced inspections.
''Companies have an obligation to comply with Commission inspection decisions and to cooperate with inspectors,'' the commission said.
Sanofi-Aventis was among several pharmaceutical companies raided in January as part of an investigation into why generic drugs were so slow to be launched in Europe. Generic medicines are made by other companies after the original developer of the drug loses its exclusive patent rights.
The company could face fines of up to 1 percent of its turnover if found to break the rules, although in practice the Commission rarely imposes such high penalties.