A Pokemon Go player called 999 to report stolen Pokemon.
The emergency call was made at 11:15 BST on Friday, the day after the hit smartphone game was launched in the UK, Gloucestershire Police said.
The operator ended the conversation "swiftly" after giving "words of advice" about when it was appropriate to call 999, a spokesman said.
The game sees players search for digital creatures in real-life locations.
Last week, a group of teenage boys entered an underground cave network in Wiltshire to search for Pokemon and got stuck 100ft below ground.
Police in Northern Ireland warned players to be careful while playing the game, and not to trespass on other people's property.
Nottinghamshire Police said it had received seven phone calls reporting "suspicious activity" in the past week, but it turned out to be people hunting Pokemon.
Three students were robbed at knifepoint while playing the game in Manchester, while Greater Manchester Police warned the app may alert predators to where children are planning to be.
In South Yorkshire, a group of players were praised after they alerted police to a burglary taking place at an industrial estate in Doncaster on Sunday.