Kaval is a Bajoran Minister of State who presses Commander Sisko to hand over the Cardassian prisoner Marritza for trial, insisting that Bajor is entitled to justice for the Gallitep labour camp.
Kaval appears in the first-season episode Duet. He is a minister in the Bajoran Provisional Government and speaks for it when word reaches Bajor that a Cardassian who served at the Gallitep labour camp is being held on Deep Space 9.
Contacting Sisko by subspace, Kaval makes it plain that Bajor expects the prisoner to be kept in custody and turned over, whatever doubts Starfleet may have about the legal grounds for holding him. He also makes sure that Major Kira, rather than Odo, is allowed to conduct the investigation.
His pressure illustrates the political stakes of the case: for the Bajoran government, the man in the cell is a symbol of the Occupation, and the question of who he really is matters less than the need for someone to answer for it.