Kansas City, Mo. ? Officials in Missouri, a hard-fought jewel in the presidential race, are sifting through possibly hundreds of questionable or duplicate voter-registration forms submitted by an advocacy group that has been accused of election fraud in other states.

Charlene Davis, co-director of the election board in Jackson County, said many of the forms came from the Association of Community Organizations for Reform Now, or ACORN. She said they were bogging down work Wednesday, the final day Missourians could register to vote.

The nonpartisan group works to recruit low-income voters, who tend to lean Democratic. In bellwether Missouri, polls show Republican presidential candidate John McCain and Democrat Barack Obama appear to have pulled even.

Jess Ordower, Midwest director of ACORN, said his group hasn’t done any registrations in Kansas City since late August. He said he was told three weeks ago by election officials that there were only about 135 questionable cards – 85 of them duplicates.

FBI spokeswoman Bridget Patton said the agency plans to investigate.