I think this was expected to be happen. Court deemed it invalid the first time they tried which was more towards beginning of scandals. It has been months now so there shouldn't be fear of him destroying evidence anymore. If he had evidence to destroy he already has done that. Only thing which could get him arrested would been if he attempt to flee the country or hide from the police and investigators, or if some new big evidence came up I guess. Doesn't seem like either is case so there is just no point arresting him right now before the court case. Investigaros and prosecution should just focus towards the court.