Chama Cha Mashinani party leader Isaac Ruto is receiving treatment at Nairobi Hospital after falling ill at his home.
Ruto was airlifted to Nairobi by Amref Flying doctors on Wednesday evening from his Tumoi home after suffering acute flu.
According to CCM Secretary General Albert Kochei, Ruto has been unwell for the last few days necessitating special medical attention.
Kochei, however, said the Bomet gubernatorial candidate is on the road to recovery and would be discharged from hospital at any time.
"H.E Isaac Ruto fell ill the last one week during campaigns but as of now he is responding well to treatment and we are optimistic he will be discharged soon," Kochei said.
The former county boss was initially suspected to be ailing from Covid-19 but tests conducted at the city hospital returned negative.
In a press statement, Kochei said it was unfortunate that Ruto would be missing during the vote tallying asking his supporters to stay calm.
Isaac Ruto trails Hillary Barchok
Ruto is trailing in the provisional results with Hillary Barchok of the United Democratic Alliance (UDA) party taking an early lead.
The vote tallying exercise is still underway at constituency tallying centres before the announcement of the final results.
Kochei at the same time said they would not accept the outcome of the results saying the results have been manipulated.
The secretary-general stated that CCM has instructed their Chief Agent Justus Mains not to accept or sign any documents endorsing the results.