Audit firm KPMG has said an estimated additional 1,037,260 dead voters could be on the roll.
It also recommended the removal of over 92,277 dead voters from the IEBC register before the August poll.
The firm has also established that more than 17,523 passports used by some of the voters are inactive.
"The IEBC should work with the civil registrar to obtain details of deceased persons registered from November 2012 to December 2016."
Gerald Kasimu, head of Information Technology Advisory Services, proposed this when he presented the audit report to chairman Wafula Chebukati on Friday.
Kasimu said they used data from the Civil Registration Department.
"We have established that another 5,427 records of voters do not have biometric fingerprint images," he reported.
The official further said 2.9 million entries in the register of 19.4 million voters contain inaccuracies of dates of birth and gender.
KPMG conducted the month-long audit from May 9. In April, the firm wrote to various government agencies asking for certified records of Kenyans to facilitate the audit.
Certified copies of the 2013 voters register, list of those enrolled in registration since that year and the register of persons were among the documents it sought.
The agency also asked for national passports register, the register of births and deaths, lists of IDs surrendered by reason of death and the 2009 housing and population census.
The IEBC will on Friday conduct end-to-end functionality tests on the Kenya Integrated Elections Management System kits.
Chebukati told journalists the equipment will show the voter identification and results transmission process.