Kosovo’s highest court has ruled that the election in February of Behgjet Pacolli as president was unconstitutional.

Pacolli, a naturalised Swiss, was elected by a slim majority after three rounds of voting by the new Kosovar parliament.

Monday’s ruling by the constitutional court came after an opposition party filed a complaint saying irregularities marred the voting process. The court ruling said Pacolli was elected by an unconstitutional procedure but did not elaborate.

It remained unclear whether there would be another vote in the parliament or if the president would have to resign. The court added that the election of Prime Minister Hashim Thaci was not affected.

The ruling was the second against a Kosovo head of state in six months. President Fatmir Sejdiu resigned in September after the same court said he violated the constitution by also serving as a party leader.

Pacolli founded Swiss-based construction engineering firm Mabetex and is estimated to be worth over SFr1 billion ($1.09 billion). He entered politics in 2006 and took a leading role in forming the New Kosovo Alliance party.

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