The head of the Organization of American States says next week's presidential election in Peru could lack credibility unless two recently-disqualified candidates are allowed to run.

OAS Secretary General Luis Almagro called on Peru to avoid a "semi-democratic" election April 10 and re-establish the political rights of Julio Guzman and another candidate barred from running last month for violating electoral laws.

Almagro's comments Friday on Twitter came after meeting in Washington with Guzman, who had been front-runner Keiko Fujimori's closest challenger.

Almagro said Peru's system for disqualifying candidates lacks guarantees and that all those running must be treated the same.

Fujimori has also come under scrutiny for allegedly handing out cash at a rally but the nation's top electoral authority Friday reaffirmed an earlier ruling clearing her of any wrongdoing.