Presidential candidate Daniel Scioli is leading exit polls in Argentina's election, but it is not clear if the vote will go into a run-off, the BBC reported on Sunday.
Scioli was handpicked by two-term leader Cristina Fernandez de Kirchner, who is constitutionally barred from seeking a third term.
A run-off would be held on November 22 if Scioli fails to secure 45% of the vote or a minimum of 40% as well as a 10-point lead over the nearest rival.