By Anamesere Igboeroteonwu
ONITSHA, Nigeria (Reuters) - A Nigerian state election was disrupted by delayed and missing materials and arguments over the voter register, organizers acknowledged on Monday, raising concerns about nationwide polls scheduled for 2015.
Saturday's vote for the governorship of the southeastern state of Anambra was seen as a test for the Independent National Electoral Commission (INEC) around 18 months before presidential elections in Africa's biggest oil producer.
"There were several issues in Anambra and I understand these could be viewed as problematic or negative," said Kayode Idowu, chief press officer to INEC Chairman Attahiru Jega.
"Lessons must be learned but we should look at it as an opportunity to enhance and fine tune our operations for 2015."
He said one INEC official had distributed the wrong voting materials to polling stations in northern Anambra, including areas that observers described as strongholds of Nigeria's main opposition party, the All Progressive Congress (APC).
The official's actions had been "suspicious" and the man had been handed over to the police, Idowu added without going into details on any charges.
Past elections in Nigeria, the continent's most populous country, have been marred by accusations of widespread fraud.
But international observers largely praised INEC for its handling of 2011's national elections, saying they were the fairest since the end of military rule in 1999.
A number of party leaders involved in the Anambra vote complained election materials were delayed, or did not arrive, at many polling stations. Thousands turned out to vote, but found their names missing from registration lists, they added.
"We are investigating the reports of late materials but the allegations about the registration list are false," Idowu said.
Some names were not included because people had not given enough information, or had fraudulently registered at several stations, he added.
INEC is planning to introduce biometric data on voter cards for the 2015 elections to limit fraud and rigging.
"There were several problems with the election that I think will be important to learn from. This could ensure people don't get complacent," one international observer told Reuters, asking not to be named because he had not finished his report.
"A major concern is the low turnout which in some cases we calculate below 20 percent," he added.
Early results showed Willie Obiano, from the outgoing governor's All Progressive Grand Alliance party, was ahead of candidates from the APC and President Goodluck Jonathan's ruling People's Democratic Party.
(Additional reporting by Joe Brock in Abuja; Editing by Tim Cocks and Andrew Heavens)