"We've spoken to dozens of people who have said they've been showing up at their polling station only to find that their names are not on the voters' registration list, or that the polling station itself doesn't exist.
"They've been driving around the capital, trying to find a place where they can vote."
Ndege said the lack of violence was one of the most positive things to come out of the day.
"There hasn't been a great deal of violence among people voting for different candidates, which was one of the huge concerns of the Nigerian people and why 23,000 police officers were drawn in to cover the election."
Opening of polling stations was delayed across the the southeastern state and various observers reported incidents of vote buying.
"If this is allowed to go on, over 80 per cent of the people will be disenfranchised and if that is the case then I will not vote."
A senior Catholic priest, who asked not to be named, told the AFP news agency: "On the whole, it's massively rigged and many people have not been given the chance to vote".
Peter Obi, the incumbent governor, said he refused to vote after finding regularities in the voters' register.
"I came out to vote and found out that in my own polling booth I am the only member of my family whose name is on the register. My brothers and my sisters, every other person's name is not there. This is very, very worrisome," he said.
"Information reaching me is that it is the same case all over the state. The consequence is that if this is allowed to go on, over 80 per cent of the people will be disenfranchised and if that is the case then I will not vote," he said.
Over 1.8 million voters were eligible to cast ballots at 4,623 polling stations scattered around Anambra.
They were choosing between 25 candidates vying for the post of governor.
Governors of Nigeria's 36 states are powerful as they pick presidential candidates at party conventions. Some of them are also controlling budgets larger than those of entire neighbouring countries.
The governing People's Democratic Party (PDP) led by Yar'adua controls all but eight of the 36 states.
Anambra is one of those that have been in opposition hands.
The election was held amid growing political turmoil in Nigeria. President Yar'Adua has been absent from the country for more than two months, receiving medical treatment in Saudi Arabia.
Yar'Adua had vowed to improve the credibility of elections in the country after a court decided he should stay in office regardless of the imperfect vote that brought him to
Presidential elections are due in April next year and will see a second successive democratic handover between civilian rulers, after a long period of military rule ended a decade ago.