The Constitutional Court has suspended legislative amendments that allow the warrantless use of tracking devices to target smugglers of products such as tobacco that are liable for excise duty.

The challenged provision, which will remain suspended until the court has reached a final decision, stipulates that approval by the head of the Financial Administration is sufficient to install location tracking devices on vehicles.

The review was requested in late January by Human Rights Ombudsman Peter Svetina, who said the provision "encroached on privacy, which is a constitutionally protected human right".

Under the challenged provision, the use of tracking devices can only be ordered based on suspicion that a serious tax offence has been committed, which the ombudsman thinks is a relatively low standard of evidence.

Originally passed last December with the votes of the Freedom Movement, the amendments to the Financial Administration Act were vetoed by the National Council. In re-vote the Freedom Movement was joined by the Left, its junior coalition partner, to override the veto.

Unusually, the two parties voted in favour after agreeing that they would ask for a constitutional review of the contentious tracking provision themselves, but the Human Rights Ombudsman beat them to it.

In an explanation of its decision, the court invoked the legal provision which allows it to suspend a law or provisions thereof prior to taking a final decision if "harmful consequences that are difficult to remedy could result from the implementation thereof".

The court highlighted the Ombudsman's argument that the implementation of the contested provision would result in an encroachment on the privacy of all persons connected to the cargo transported in the vehicle that is being tracked.

There is also the risk that the state authorities become aware of the location and movement of these persons in public and private spaces and thus getting to know the details of their private lives.

The court acknowledged noted that the suspension could have consequences that are difficult to remedy on the Tax Administration's ability to fight serious cases of tax evasion.

It added, however, that neither the government nor the National Assembly have proven that financial investigations would be completely impossible without the contested powers granted to the tax inspectors.