Premiership Rugby have launched an investigation after a number of false positive Covid-19 tests.
But an operator error at Premiership Rugby's testers Randox Health saw the number of positive cases incorrectly reported to the league.
There were actually just two positive cases in 989 tests across the Premiership this week.
"As a result of routine risk analysis Randox discovered that in an isolated incident, operators failed to follow the established and robust procedures that Randox have in place for Covid-19 testing. Randox apologises for any inconvenience caused," a spokesman for Randox said.
"Randox have introduced innovative robotic systems to ensure that this type of human error cannot reoccur."
There are no games for Premiership sides this weekend as European games have been suspended due to French concerns over travelling to the UK in the wake of the increase in Covid-19 cases.
"This issue has created disruption at our clubs, and especially at Bath Rugby who had isolated a number of players and temporarily closed their training ground after receiving their results early on Tuesday morning," said Premiership Rugby's rugby director Phil Winstanley.
"The health and safety of everyone involved with Premiership Rugby is a priority for us so this matter will be thoroughly investigated."