By Steve Olafson

OKLAHOMA CITY (Reuters) - Voting ended on Saturday to pick a principal chief of the Cherokee Indians, the nation's second largest tribe, following vote tampering charges and a fight with some African-Americans over tribal membership.

Unofficial results of the election are expected on Wednesday.

The election was initially held June 25, but it did not produce a clear-cut winner after four recounts produced four different totals and two different winners. Charges of vote tampering were raised but never proven.

When the Cherokee Supreme Court ordered a new election for September 24, the chairman of the tribe's election commission resigned in disgust, saying the commission had been wrongfully portrayed as "incompetent and ineffective."

The tribe's high court then added further fuel to the political fire when it issued a ruling August 21 that banished 2,800 black members from the tribe. This led to allegations that the move was designed to help Chad Smith, the 12-year incumbent who appointed the justices to the bench.

The black Cherokees, known as freedmen because their forbears were slaves owned by tribe members in the pre-Civil War era, support the challenger in the election, Bill John Baker, whom they consider less hostile to their membership.

The freedmen and the federal government maintain they are rightful citizens of the tribe because of the Treaty of 1866 with the U.S. government. Cherokees say the tribe has the right to require an ancestral tribal blood link to be a citizen.

The freedmen citizenship issue has festered for decades.

Days before the September 24 election, an out-of-court settlement temporarily restored the freedmen voting rights, as well as their tribal citizenship, after the federal government withheld $33 million in housing funds and threatened not to recognize the election results.

Five extra voting days were added to the election as part of the settlement.

The Carter Center in Georgia sent observers to the election, even though the nonprofit organization founded by former President Jimmy Carter has a policy of helping monitor elections only in foreign countries.

Avery Davis-Roberts, assistant director of the Democracy Program at the Carter Center, said the organization made an exception because it sent representatives to a divisive Cherokee chief election in 1999.

She said that the Cherokee tribe's status as a sovereign nation led the Carter Center to waive its usual jurisdiction limitations.

In a telephone interview from the tribe's base in Tahlequah, Oklahoma, Davis-Roberts said no one has lodged any complaints about the election process.

"It's been pretty smooth," she said. "Everybody is really hoping this would be an easy process and would have a clear outcome so everyone can move on."

(Editing by Greg McCune)