Prosecutors in Peru are investigating potential irregularities in presidential candidate Keiko Fujimori's campaign finances, the attorney general said on Friday, confirming press reports based on leaked documents ahead of the June 5 election.

The unit on money laundering in the attorney general's office is probing campaign donations that Fujimori's center-right party collected from two cocktail fundraisers and her husband's purchase of land, Attorney General Pablo Sanchez said.

Fujimori, neck-and-neck in most opinion polls with her centrist rival, Pedro Pablo Kuczynski, denied any wrongdoing and said she was the victim of a smear campaign.