ADX Energy (ASX:ADX) warned that a judicial review by the Constitutional Court of Austria could cause an interruption to the Welchau-1 well testing program, according to a filing with the Australian bourse on Tuesday.

ADX drilled the Welchau-1 well in Upper Austria during the first quarter of 2024, and the well intersected three primary carbonate reservoirs, which were considered promising for testing and ongoing appraisal.

Environmental organizations in Austria had filed appeals with an environmental authority in the European country, objecting to the environmental clearance the firm had received and seeking a suspension of operations.

The suspension was rejected by the environmental authority. However, following a judicial review, the constitutional court decided to repeal the suspensive effect article on the basis that it was not constitutional.

The testing of Welchau-1 is expected to be suspended until the State Administrative Court of Upper Austria clarifies the situation, according to advice received by ADX's lawyers.

It is monitoring the well to evaluate the rate of pressure build-up, in order to determine the nature of its fluid flow.

ADX holds a 75% economic interest in the Welchau discovery and other emerging prospects in the Welchau Investment Area located in ADX's ADX-AT-II license in Upper Austria.