The Fiji Public Service Association says its members are being victimised amid allegations of widespread corruption and collusion at the Revenue and Customs Authority.
The authority has sacked one employee, claiming he leaked confidential information which led to the allegations, and suspended two others on half pay.
The secretary of the union, Rajeshwar Singh, says the Director General of Inland Revenue Services, Abdul Hakim was suspended after the authority received an anonymous letter alleging misconduct.
Mr Singh says he believes members of the authority are retaliating after the union successfully sought an injunction against it.
"It's a clear victimisation of FPSA members. It has come to a stage where there is harassment of our members because we have taken the authority to the high court and we have got an injunction against them not to implement the job relation and restructure project."
The secretary of the Public Service Association, Rajeshwar Singh
The corruption allegations, which involved the authority's chief executive, Sila Kotobalavu, were made by Senator Felix Anthony.
The PSA says it's taken its complaints to the Minister of Labour, Kenneth Zinck, and the Human Rights Commission.