Kenya's veteran opposition leader Raila Odinga filed a challenge to the results of this month's presidential election in the Supreme Court on Monday, his legal team said, the latest twist in a political clash that has gripped East Africa's powerhouse.

"What we did this morning is to file the online copy," lawyer Daniel Maanzo told Kenyan television channel. "After today there will be four days for the other parties to reply."

A source at the judiciary confirmed they had received a copy of the file.

Last week the election commissioner declared Deputy President William Ruto had won the election by a slim margin, but four out of seven election commissioners dissented, saying the tallying of results had not been transparent.

Last week Odinga said the results were a "travesty" but said he would settle the dispute in court and urged supporters to remain peaceful.

This is Odinga's fifth stab at the presidency; he blamed several previous losses on rigging. Those disputes triggered violence that claimed more than 100 lives in 2017 and more than 1,200 lives in 2007.

In 2017, the Supreme Court overturned the election result and ordered a re-run, which Odinga boycotted, saying he had no faith in the election commission.

This time, Odinga is backed by the political establishment. President Uhuru Kenyatta endorsed Odinga's candidacy after falling out with Ruto after the last election.

At stake is control of East Africa's wealthiest and most stable nation, home to regional headquarters for firms like General Electric, Google, and Uber. Kenya also provides peacekeepers for neighbouring Somalia and frequently hosts peace talks for other nations in the turbulent East Africa region.

Petitioners must submit their complaint to the Supreme Court within seven days of the results being declared.

The court next conducts a status conference with all parties to define the hearing schedule and ground rules.

The constitution requires the nation's highest court to issue its decision within 14 days of the lawsuit being filed.

Due to the tight schedule, it normally issues a summary judgment within 14 days, followed by more thorough decisions from each of the seven judges at a later date.