Governor Mike Sonko denied colluding with election officers to tamper with results.
Dr Evans Kidero said that more than 60 per cent of the Forms 37A used to declare Mr Sonko the winner had anomalies.
Nairobi Governor Mike Sonko has dismissed claims by his predecessor Evans Kidero that the election was rigged in his favour.
In a reply to a petition in court, Mr Sonko said Dr Kidero has made unsubstantiated claims, which are not backed by facts. He maintained that the election was free, fair and transparent and conducted in accordance with the principles, spirit and intention of the Constitution.