Mol, the Hungarian energy group, on Wednesday accused OMV, its Austrian rival, of acting as a “front” for Russian interests in a deal involving a 21 per cent stake in Mol.

Zsolt Hernadi, Mol’s chairman, made the claim before a Hungarian parliamentary committee looking into the €1.4bn ($1.9bn) sale of the stake, which has raised a political storm in Budapest and prompted questions about the impact on the country’s and the European Union’s energy security.