People watch on television the announcement of the winner of polls in Kenya's repeat presidential election in Kisumu, Kenya October 30, 2017. REUTERS/Baz Ratner

(Reuters) - A former lawmaker filed a petition at Kenya’s Supreme Court on Monday challenging the results of last month’s presidential election, a Reuters witness said, opening the door to potential legal challenges to President Uhuru Kenyatta’s re-election.

The petition, filed by former legislator Harun Mwau, seeks to overturn Kenyatta’s victory in the Oct. 26 election, which was held after the Supreme Court nullified Kenyatta’s win in an Aug. 8 presidential election on procedural grounds. The grounds for Mwau’s petition were not immediately clear since his lawyer did not answer questions.