The South Africa squad has returned a full set of negative Covid-19 results, meaning the ODI series against England will start on Sunday after the tour was thrown into doubt by the positive test that was announced shortly before the first ODI was due to start in Cape Town on Friday.

"Cricket South Africa (CSA) is pleased to announce that the entire Proteas team has returned negative results from the COVID-19 tests that were conducted yesterday evening in Cape Town," a CSA statement said on Saturday morning.

The entire South Africa squad was retested on Friday evening following the confirmed case which brought into question the safety of the biosecure bubble both teams are in. CSA said it had looked into the possibility of a breach at the team hotel and was satisfied protocols were being followed.

If there had been further positive cases emerge from this latest round of testing it is highly likely that the tour would have been called off.

"There is a cause for concern and England has expressed a concern. England are questioning the confidence they have in the bio-secure environment and rightfully so," Dr Shuaib Manjra, CSA's chief medical officer, said on Friday. "If there has been a player who tested positive in the last week, they have cause for concern and we respect that concern.

"This test surprised us because we have confidence in the integrity of the bio-secure environment. Further tests indicate that this is a more recent case that occurred within the bio-secure environment. So clearly there seems to be some kind of breach which we have investigated in great detail to try and determined where this happened."

The matches will now take place on Sunday, Monday and Wednesday, with England flying back to the UK on Thursday.

South Africa's first attempts at hosting cricket in a biosecure environment have so far encountered several setbacks. Two players, understood to be Andile Phehlukwayo and David Miller, tested positive in the build-up to the T20I series, and the team's intra-squad warm-up match had to be cancelled.

A third positive result when the squad was tested before the ODIs led to the postponement of the opening match an hour before it was due to start, and raised the possibility of the tour being abandoned.