Kiplagat died at the Nairobi Hospital at 3 am on Friday, according to officials who spoke to his family.
It comes just two days after that of Nicholas Biwott, a former powerful Cabinet Minister in former Presidential Daniel Arap Moi government. Biwott also died at the Nairobi Hospital where he had been rushed for emergency treatment on Tuesday morning.
Others include Interior Cabinet Secretary Joseph Nkaissery who collapsed and died on Saturday morning. He had suffered a heart attack.
Two weeks ago, Senator Godfrey Gitahi, popularly known as G.G Kariuki also died following a long illness and was set to be buried on Friday. Memorial services were held separately on Thursday for Nkaissery and Biwott.