Former Imenti Central MP Gideon Mwiti died in hospital early Sunday while undergoing treatment for diabetes.
His personal assistant, Mr Frank Muthuri, said he died at Kenyatta Teaching and Referral Hospital at 4am, after developing complications, two hours after he had been rushed there.
Mr Muthuri said Mwiti, a former Alliance Party of Kenya (APK) MP, had been battling with diabetes for several years.
Mwiti died while being attended to, the personal assistant said, adding he had been well until Saturday night.
"He was jovial yesterday evening and chatted with friends on social media before retiring to bed," he said on Sunday.
Mwiti, who served as MP from 2013 to 2017, retired from active politics in 2017 to venture into private business.
In 2015, he faced allegations of raping a woman in Nairobi. He was charged alongside a doctor accused by police of aiding and abetting the crime by conducting an involuntary HIV test on the complainant.
Mwiti denied three counts of rape, intimidation and assault in the case that was yet to be concluded.
In April, he requested that the case be heard in open court, instead of virtually.