Election Observation Group (ELOG) wants the electoral agency to clean up the voters' register before elections.
In its report released yesterday, the election observers' findings reinforced an earlier audit by KPMG, which had detected some anomalies in the voters' register.
The report noted that the Independent Electoral and Boundaries Commission (IEBC) maintained 171,476 voters in the register who had invalid Identification Cards and whose details could not be verified in National Registration Bureau database.
ELOG also wants the IEBC to shed light on how many voters were included in the register from the 17,523 whose details were not found in the data provided by the Directorate of Immigration.
The report also want the IEBC to confirm the status of 98 voters whose details were found to have been registered under diplomatic passports and their data had not been provided.
The ELOG chair Regina Opondo, who released the report, said public officers were violating election laws by engaging in open campaigns for their preferred candidates.
"There were also massive voter bribery across the counties during campaigns," said Ms Opondo. [Lucas Ngasike]