England and South Africa are awaiting the results of the Proteas' latest round of Covid-19 tests, amid concerns that any new cases could see the remainder of the tour cancelled.

The first one-day international between the sides was postponed barely an hour before the scheduled start of play at Newlands on Friday, following the revelation that an unnamed South Africa player had tested positive for coronavirus.

The news followed two prior cases in the home camp ahead of the recently completed Twenty20 leg of the trip and was understood to have caused considerable disquiet in the England set-up as well as doubts over the effectiveness of the bio-secure bubble.

"We did a scheduled Covid-19 test yesterday for the team and unexpectedly had a positive. Further tests indicate this is a more recent infection that occurred within the bio-secure environment, so clearly there seems some kind of breach.

"We've investigated in great detail to try and determine where this happened. We've tried to recount events – speaking to players, looking at security cameras, looking at other information and we haven't been able to identify where that source was.

"I'm fairly convinced that 99 per cent of the time this environment is working, but there may be a breach that's unknown to us, that may have caused this positive test."