A Pokemon Go player in England called 999 to tell police there that someone had "stolen their Pokemon".
The gaming fan decided to contact Gloucestershire Police as an emergency while using the hugely popular app on the day after its UK launch.
Police gave the player "words of advice" on when it is appropriate to call 999.
The craze, which has reached fever pitch in the US, has sparked a string of incidents in the UK in the past week.
A security alert was triggered at Leicestershire Police headquarters on July 15 when players gathered at the site - and Nottinghamshire Police pleaded with users to consider others after two teenage boys accidentally spread fear among villagers in Normanton-on-Soar as they searched for Pokemon by torchlight in the early hours of July 12.
The app was only officially launched for all users on July 14, but some players had managed to get early access by working around country restrictions.
Three students had their phones stolen in a park in Hulme, Manchester, on Saturday while they were using the app, after forces including Greater Manchester and Nottinghamshire Police warned users that criminals could use the app to draw in victims.
The game allows players to buy a "lure module" to attract Pokemon - which as a result will also lure in other players.
Concerns have also been expressed about the safety of children playing Pokemon Go.
Greater Manchester Police warned that the lure modules may alert predators to where youngsters are planning to be, and the NSPCC claimed that "basic safety standards appear to have been overlooked" in the creation of the app.
A spokesman for the UK's National Crime Agency said: "We advise parents and young people to be aware of the many apps which can share personal and location data and, as with any activity in public spaces, those taking part in augmented reality gaming should remain mindful of their surroundings and take care to avoid risky situations."
App maker Niantic said: "We take player safety seriously and want everybody to have a fantastic time exploring while safely playing Pokemon Go.
"We encourage all people to be aware of their surroundings and to play with friends or family, especially when you're exploring unfamiliar places.
"Please remember to be safe and alert at all times, don't drive and play, abide by local laws, and respect the locations you visit and people you meet during your exploration."
However, the app has also been used in the fight against crime.
South Yorkshire Police praised a group of players who came across a burglary at an industrial estate in Doncaster on Sunday and alerted the force.
An entry on the SYP Operational Support Facebook page said: "Our control room took a call from a group of friends. These friends had been in the Wheatley area of Doncaster playing #PokemonGo, looking for those pesky little creatures on their app. They travelled down a side road into an industrial (estate) and saw something suspicious in a builders yard. Dilemma ... search for Pokemon or call the cops?
"Thankfully these budding search heroes called 999 to report what they had seen."
And a crime scene investigator for Surrey and Sussex Police, Chris Gee, appealed to players who may have witnessed a burglary at a Tesco garage in Durrington, West Sussex, just before 1am on Saturday July 16.
He made a plea on Twitter after noticing that several cars had driven past the petrol station at the time of the break-in, and realised that a community centre opposite is a Poke Stop, where players can receive useful items within the game.