Munster have revealed there have been nine positive cases of Covid-19 among their traveling players and staff in South Africa.
This followed another round of PCR testing in Cape Town.
The remaining party of 38 have returned negative results and are isolating in their hotel rooms.
Another round of PCR testing will take place today and upon results of those, Munster may be able to make a determination about travel back to Ireland for those who are not carrying the virus.
The individuals affected by the positive cases - the nine today and a previous case, will remain in Cape Town until the end of their isolation period.
Today's news places the ability of Munster to adequately prepare for and fulfil the Heineken Champions Cup game against Wasps on Sunday December 12th in doubt.
It's as people in England face being fined if they fail to wear a face-covering in shops and on public transport, from today.
Restrictions to tackle the spread of the Omicron variant also means anyone arriving in the UK, excluding Ireland, will have to isolate until they get a negative PCR result.
The UK's Junior Health Minister, Gillian Keegan's refused to rule out putting European countries on a red travel list.