A review of voter registration lists found the omission of thousands of legitimate voters, the National Democratic Institute said Friday.
By auditing both National Election Committee voter registration and voter deletion lists and comparing the results, the group found that 10 percent of the deleted names were those of eligible voters, about 57,000 of them.
The group noted, however, that 500,000 invalid names had been removed from the voter registry.
NDI recommended the NEC take measures to ensure eligible voters be restored to the registry. If their names are not re-instated, the voters will be excluded from July's general election.