France have suspended training ahead of Sunday's Guinness Six Nations game against Scotland following another positive Covid-19 test among the playing squad.
Tournament chiefs gave a green light on Wednesday to the match in Paris going ahead as planned.
The Stade de France showdown had been thrown into major doubt following a Covid-19 outbreak among Les Bleus players and management.
The go-ahead followed a fresh round of negative results, but latest developments will inevitably put the fixture in jeopardy again.
In a statement, the French Rugby Federation said: "Following the RT-PCR tests carried out this Wednesday, February 24 in the evening, and the appearance of a positive case within the squad of players, the FFR medical committee met this morning and decided to suspend training this day.
"The entire group is in isolation in accordance with health protocol.
"The FFR is in close contact with the Six Nations committee."
France's coronavirus outbreak forced 10 of their top stars into quarantine, including scrum-half and 2020 player of the championship Antoine Dupont and captain Charles Ollivon.
Les Bleus stand top the Six Nations table after two rounds following a comprehensive win against Italy and a narrow victory over Ireland, both away from home.
This weekend's encounter was placed under threat when flanker Ollivon, prop Cyril Baille, hooker Peato Mauvaka, lock Romain Taofifenua and full-back Brice Dulin became the latest members of Fabien Galthie's squad to test positive.
Nine of the 23-man squad that sent Ireland spinning to a 15-13 defeat 11 days ago were since found to have contracted the virus.
In addition to positive tests produced by players, head coach Galthie is among members of France's management team in self-isolation.
