The visitors are due to face the Kiwis in 3 T20Is and 2 Tests from December 18.
The board has started the probe after learning that some players had complained of coughing, fever and sneezing, possible Coronavirus symptoms, while playing the Quaid-e-Azam Trophy, just a few days before flying across to the Kiwiland.
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“These players were deemed to have viral infections due to changing weather and later also tested negative in the COVID-19 tests carried out in Lahore by the board," a PCB source close to the matter was quoted as saying by PTI.
"But they tested positive after reaching Christchurch where the entire squad is now quarantined at a managed facility after the 10 positive tests."
The source said some of the players who gave initial positive cases were the same who complaint of fever playing the domestic tournament.
Majority of the touring Pakistani players belong to two provincial teams and some of them played together for one Pakistan Super League (PSL) franchise.
"The source confirmed that a foreign player who played for the particular franchise is also undergoing eight days of isolation after he returned positive results upon his arrival to his home country," reported PTI.
This, after the news that Sohail Tanvir, who took part in the PSL playoffs, also tested positive upon reaching Sri Lanka for the Lanka Premier League (LPL).
Tanvir later gave a negative test, but with advice from Kandy franchise and its medical officers that he'll be taking a health risk in going ahead with the LPL participation, the left-arm pacer returned home.
The PCB is facing scrutiny over its testing arrangements after the players who have tested positive in New Zealand, all gave negative tests when they got together in Lahore before departing.
Apart from multiple cases, the visitors also breached New Zealand's quarantine protocols and have been given a "final warning" on the matter, besides being denied the exemption to train while going through their managed isolation. All those currently positive are isolated separately.