In an email to a complainant, which was obtained by Herald, the commission's legal adviser said the forwarding of the screenshot was done "inadvertently".
"While we would normally provide a candidate who is the subject of a complaint with an image to show what has been complained about, it is not the Commission's practice to identify complainants," he wrote.
"I apologise for this information being inadvertently provided to the candidate's team."
When contacted, Kang said he had not been approached by the commission and added that he did not wish to speak to the Herald.
Maori Party president Tukoroirangi Morgan has called a press conference in Auckland this afternoon to respond to the cash credits allegations.
The woman said she took the screenshots "out of concern" and had forwarded them on to a friend.
"I am very upset that the commission had released them, because it was supposed to be confidential," she said.
The complaints alleged Kang's campaign offered "hong bao dollars" or online money envelopes on WeChat.
Hong bao is a Chinese tradition of gifting money in a red envelope usually on special occasions, and was adopted for the digital age when WeChat introduced the ability to distribute virtual red envelopes of money to contacts and groups via its mobile platform for the 2014 Chinese New Year.