South Africa's one-day international against England in Paarl on Sunday has again been called off after two members of the England tour party returned positive Covid-19 tests.
The start of the game was initially delayed while officials waited for the results of a new round of testing from the England camp, before the decision was made to cancel the game altogether.
Cricket South Africa and the England and Wales Cricket Board said in a joint statement that two members of England's touring party had now tested positive for the virus, although further tests were required.
It was not clear if those involved were England players.
"Cricket South Africa [CSA] and the England and Wales Cricket Board [ECB] have agreed to cancel today's Betway One-Day International series opening match, which was due to take place in Paarl," the governing bodies said.
Ashley Giles, the managing director of England Men's Cricket, said: "We regret that we are unable to play in today's ODI, but the welfare of the players and support staff is our primary concern and whilst we await the results of further tests the medical advice from both teams was that this game should not take place.
"We remain in constant dialogue with Cricket South Africa and will continue to work closely with them to determine how best to move forward."
CSA said the England players and management underwent an additional round of tests on Saturday evening after two members of staff at their hotel tested positive for the virus.
England had previously expressed concern over the strength of the bio-secure environment.
Roy Davies, general manager of the Vineyard Hotel where the teams are staying, said the hotel is still investigating how two staff members contracted the virus.
"At this stage, it is not clear how the staff members became infected as neither have left the bio-secure area since 16 November and they do not work on the same team or in the same area," he said.
"Our Covid-19 response team is endeavouring to establish all the facts and contact tracing is underway."
A decision on whether to hold the final two games of the ODI series - scheduled to be played at Newlands on Monday and Wednesday - will be made after results are ratified, the ECB said.
The first ODI, originally due to be played in Cape Town last Friday, was postponed after an unnamed South Africa player tested positive.
It is the seventh Covid-19 related incident on the six-match white-ball tour, two of which occurred in the South Africa camp before the matches started. It is the second involving a bio-secure environment.
Former England captain Mike Atherton, now a television commentator and journalist, said he feared the entire series could be under threat.
Atherton said the new positive cases had "ramped up" the concern that the England camp already felt after the opening match had been postponed.
"Certainly this match is off and I would be pessimistic about the other games," said Atherton.
The tour is providing much-needed revenue for embattled Cricket South Africa, who have already had to cut short a tour of India, and missed out on trips to Sri Lanka and the West Indies due to the coronavirus.
South Africa and England completed a three-match Twenty20 International series this week that was won 3-0 by the visitors, and were due to play three more ODIs.
South Africa's director of cricket Graeme Smith said they hope the final two matches could be played.
"We are deeply regretful of the situation we find ourselves in after the amount of time and energy that has been put in place to host a successful tour," he said.
"We are in continuous talks with the ECB as we navigate the situation under the guidance of our combined medical teams."
