A West Australian police officer convicted two years ago of unlawfully using a tracking device to monitor a mate's girlfriend has been awarded legal costs after successfully appealing against the decision.

Ian Gordon Tower was a detective sergeant with the state's Organised Crime Squad in September 2012 when he allegedly placed a tracking device in the car of a colleague's partner.

Tower was convicted in the Perth Magistrates Court in February 2015 following a Corruption and Crime Commission (CCC) investigation and received a spent conviction, but was fined $4,000 and temporarily stood down from operational duties.

His colleague, who could not be identified, was also fined and moved out of his role in internal affairs.

However, WA's Court of Appeal last year ruled the CCC did not have the legislative power to prosecute people it had investigated, a ruling which stemmed from a case involving a Broome police officer accused of assaulting two detainees.

That ruling sparked concerns that dozens of cases the CCC prosecuted in the Magistrates Court could be subject to appeal.

Tower's lawyers filed a notice of appeal on behalf of their client in October last year, and the State Solicitor's Office has conceded the case.

Tower has also been awarded $14,982 in a ruling by Justice Peter Martino to cover legal expenses he incurred during his Magistrates Court trial.

The parties agreed no costs would be sought from Tower for his appeal.

In response to a query, police said Tower remained a serving officer and was currently on operational duties.