JEFFERSON CITY, Mo. -- A union ousted as the representative for state prison guards is contending that administrators unfairly influenced an election to get rid of the union.

In a hearing Tuesday before the State Board of Mediation, union members testified that mid- and upper-level administrators openly supported a rival correction officers' association that led the effort to decertify the American Federation of State, County and Municipal Employees.

In April, corrections officers voted 2,879 to 1,503 to end their affiliation with a branch of the AFSCME union.

Although union officials contend the election environment was tainted against them, the state attorney general's office maintains the election was fair.

So does the Missouri Correction Officers Association, a rival group that has dues-paying members but does not consider itself a union. The association collected petition signatures to force the referendum on AFSCME representation.

"The outcome of the election represents an overwhelming voice of the members of the bargaining unit that AFSCME should no longer be their representative," John Landwehr, a Jefferson City attorney representing the Correction Officers Association, told the state board.

Among the witnesses for the union was Buddy Gray, a correction officer from the Western Missouri Correctional Center in Cameron. He said supervisors -- including the prison's superintendent -- authorized the distribution of anti-union materials to employees.

"Management was overseeing the election -- there's no question about it," said Gray, a union member.

But the correction officers association presented guards who said they felt no pressure from supervisors. Unlike the AFSCME union, the corrections officers association has some members in supervisory positions.

John Birch, chairman of the three-member state panel hearing the case, said the board is well aware there "was a caustic atmosphere in the Department of Corrections" because of the rivalry between the two groups.

The board was expected to issue a decision at a later date.