Romania's presidential race was neck-and-neck on Sunday, with exit polls showing frontrunner Prime Minister Victor Ponta tied with his opponent, centre-right mayor Klaus Iohannis.

One poll showed Ponta on 50.9 percent of the vote and Iohannis on 49.1 percent in Sunday's runoff, another showed them tied at exactly 50 percent. A third poll showed Iohannis at 50.9 percent.

Ponta had comfortably beaten Iohannis in the first round on Nov 2 and led opinion polls ahead of Sunday's vote.

The final result is much tighter than in the first round. That could bring into play the votes of Romania's large and growing diaspora, who helped tip the balance in a tight race at the last election and are now widely seen as against Ponta.