The Kenyan chief prosecutor’s office has ordered a police investigation into “irregularities and illegalities” allegedly conducted by the country’s election commission during the presidential poll last month, which has been annulled.

Director of Public Prosecutions Keriako Tobiko on Sunday instructed Kenya’s criminal investigations department and anti-corruption commission to complete wide-ranging probes into the alleged offenses of the Independent Electoral and Boundaries Commission (IEBC) within a 21-day period.

Tobiko ordered “thorough, comprehensive and expeditious investigations... with a view to establishing whether electoral and/or other criminal offenses... may have been committed by the IEBC officials.”

The chief prosecutor also said that he had designated a team of senior prosecutors to provide technical guidance and assistance to the investigation teams.

Kenya’s Supreme Court invalidated the August 8 presidential election following a legal challenge from opposition leader Raila Odinga.

Incumbent Uhuru Kenyatta had been declared the winner of the election with 54 percent of the votes, but Odinga claimed that the victory had been a result of hacking and manipulation of the electronic vote counting system, without presenting evidence.

The claim sparked massive protests in two major slums in the capital, Nairobi, and in the west of Kenya, where Odinga enjoys huge support.

Dozens have reportedly been killed in the violence while the international community has called on Odinga to restrain his supporters.