Saints were scheduled to take on Tigers on Saturday but the clash was cancelled after the black, green and gold returned a number of positive tests in this week’s round of PCR testing.
Further players were identified as close contacts and therefore also placed into isolation.
Saints were advised by Public Health England to keep their training facility closed and not to play against their East Midlands rivals, who have since been awarded four points.
Therefore, under Premiership Regulations, the match was cancelled.
A further round of testing will be undertaken on Monday, January 11.
Saints CEO Mark Darbon said: “Cancelling the East Midlands derby was an incredibly frustrating outcome for the club, given that after rigorously following the protocols laid out for us, we still comfortably had enough of our squad healthy and available to field a strong matchday 23 if required.
“However, we respected the advice we were given by Public Health England, and accepted their judgement that cancelling the game was in the best interests of players, staff and officials.
“Before last week, we had seen no positive Covid-19 results at the club for just shy of two months, and the increased number of positive tests reflect the wider community challenge we are all facing at present.
“All the individuals at Saints impacted by Covid-19 have been isolating and are recovering well.”
The decision was made by a Premiership Rugby panel comprising chairman Andy Higginson, CEO Darren Childs, and rugby director Phil Winstanley.
A Premiership Rugby spokesperson said: “Following the recommendation from Public Health England that Northampton Saints’ Gallagher Premiership Rugby Round Six fixture against Leicester Tigers should be cancelled as a result of Covid-19, Tigers have been awarded the win and four league points.
“Northampton Saints shall be deemed to have lost the match but awarded two league points. The match score shall be recorded as 0–0.
“The health and safety of players, staff, management, officials and supporters is our only priority, so following advice from Public Health England the correct decision was taken to call the game off.”