British Athletics has written to European Athletics to express its concerns over coronavirus protocols at the European Indoor Championships in Torun earlier this month.
Ten members of the travelling party of athletes and staff have now tested positive for the virus, following an initial case which saw the entire squad ordered into self-isolation in the Polish city.
The PA news agency understands that among British Athletics' concerns were a lack of space for social distancing and protocols not being adhered to or properly policed, including mask-wearing not being enforced.
Pole vaulter Holly Bradshaw revealed on social media that she was one of the athletes to test positive, writing that she had "minimal symptoms" and still felt "positive, optimistic and energised".
Multiple athletes from France and Ukraine have also reportedly tested positive after returning from the Championships, while members of the Ireland squad were required to self-isolate after a positive case.
Polish sprint star Ewa Swoboda failed a test during the Championships and was unable to defend her 60 metres title, while Poland's 4x400m men's relay squad were also forced to withdraw.