Witnesses say the vehicle had two occupants at the time of the accident.
Doctors told the Nation that the CEC, whose left leg was fractured, also complained of chest pains.
Muranga County Executive Member for Water and Cooperatives Paul Macharia is nursing serious injuries at Muranga County Referral Hospital after being involved in a road accident that killed his relative on Sunday morning.
According to eye witnesses, Mr Macharia's vehicle was speeding when it lost control and hit trees at Kaharati along Kenol- Muranga road.
Mr John Kamau, a witness said the vehicle had two occupants at the time of the accident.
"The vehicle was moving at a high speed, we heard a huge bang and when we looked we saw two people stuck inside the car," he said.
Muranga County Police Commander Josephat Kinyua said Mr Macharia lost control of the vehicle and veered off the road before hitting a tree in the 8am Sunday accident.