The inquiry last month published its report into the mistreatment of suspects arrested during the investigation into the death of cattle dealer Richie Barron.
The tribunal has found that Mr Barron died in a hit-and-run, but gardaí wrongly treated the case as murder.
The inquiry heard evidence in 12 submodules, one for each suspect, before preparing its report.
The most senior garda not to receive full costs is Det Insp Michael Keane, who was awarded 75 per cent of the costs for his evidence in relation to Michael Peoples, one of the 12 innocent people arrested. The tribunal said Det Insp Keane did not give full co-operation.
Garda John Harkin and Garda Tina Fowley were both commended for giving evidence of a “conspiracy” to alter interview notes, and awarded full costs.
However, another garda, Sgt Brian McEntee, “gave nothing like full co-operation to the tribunal”, instead giving “evasive evidence”, and was denied his costs.
Garda Fowley was also awarded costs for her evidence relating to the detention of Katrina Brolly.
Former sergeant John White, who ultimately came forward and admitted Mrs Brolly was mistreated, was also awarded his costs.
However, the former officer received only 75 per cent of his costs relating to the treatment of Seán Crossan, and his evidence in the bugging submodule was rejected and he was refused costs.
Garda Fowley was also refused her costs in the bugging submodule.
Former garda John Fitzpatrick and Sgt John Melody, the two gardaí present when Frank McBrearty jnr made a false confession to a crime that never happened, were awarded 80 per cent of their costs. The tribunal found the confession did not come about in the manner they described