The incident happened at Russell Crescent in Lerwick on Friday, May 14, when Shetland was still under Level 3 coronavirus restrictions – meaning it was not permitted to meet any other households indoors.
After police responded to the report and discovered the house gathering, six people – including some officers – were issued with fixed penalty notices.
Superintendent Maggie Pettigrew said that she was “extremely disappointed” in the officers involved.
She said: “The vast majority of people in Shetland have been sticking to the rules to suppress the spread of coronavirus and I would like to thank our community for this.
“It is extremely disappointing that a small number of police officers were involved in a gathering in breach of the regulations on Friday, 14 May.
"Their actions undermine the sacrifices you have all have made in the last year and I appreciate many of you will be upset about this incident.
“They have been given fixed penalty notices and reminded of their responsibility to set an example to others."
Shetland was moved to Level 1 on Monday, May 17, which allows six people from up to three different households to socialise in a private indoor space.
A Police Scotland spokesperson said: “Officers were called to a report of a gathering in breach of coronavirus regulations within a property in Russell Crescent, Lerwick, at around 6.15pm on Friday, May 14, 2021.
“Six people have been issued with fixed penalty notices and the gathering was dispersed.”