Around 25 used coronavirus test kits were mistakenly handed out by the council in Birmingham.
Students living in the Selly Oak area reportedly found used swabs when they opened the testing kits.
Birmingham City Council has said the incident involving their distribution service is being “reviewed”.
The tests were handed out as part of their drop off and collect service to help tackle coronavirus cases.
It comes as more than 300 students at the University of Birmingham have tested positive for Covid-19.
The Birmingham branch of the University and College Union (UCU) has threatened a ballot for industrial action if face-to-face teaching is not moved online to help avoid the further spread of coronavirus.
Sophie Dunne, a second year student at the University of Birmingham, reportedly told student newspaper Redbrick that several students emerged from their homes to alert the council workers about the used tests.
A statement from Birmingham City Council said: “We are aware that a small number of tests were mistakenly given out during Drop and Collect activity in Selly Oak yesterday (October 13).
“We want to reassure residents that none of these tests were reused and while the outer packaging on one was opened, the inner pack containing the swab remained sealed and secure so there is no risk of contamination.
“The team was alerted within five minutes that the wrong tests had been given out and steps were taken immediately to rectify the mistake. Drop and Collect is a vital part of helping to tackle the spread of Covid in our city, with around 100,000 tests being undertaken to date.
“The circumstances around this incident – which involved seven houses and 25 kits – is being fully reviewed and any required changes to process will be implemented.”
Birmingham is a Tier 2 area of the country which means households are not able to meet indoors.
The UCU has called on the University of Birmingham to switch learning online as they warn attending lessons on campus is “putting the health and safety of staff, students, and the local community, at risk.”
A University of Birmingham spokeswoman said: “We are extremely disappointed that UCU have decided to declare a dispute before the agreed procedures to try and reach a resolution have been exhausted.
“The safety and wellbeing of our staff and students is our priority and our campus unions, including UCU, have attended weekly meetings with the university through the summer to discuss the institution’s plans and all building Covid risk assessments were shared with the unions to review.”