The feature has become massively popular among users, and it is estimated 100 billion digital red envelopes were sent over Chinese New Year 2017.
Screenshots show Wetex's campaign manager messaging people on WeChat using the red envelope symbol.
The Electoral Commission confirmed to the Herald it is investigating a complaint in relation to messages posted on WeChat.
"The Electoral Commission has received complaints about the use of 'hong bao dollars' on WeChat as part of Maori Party candidate Wetex Kang's campaign," a commission spokeswoman said.
"The Commission is looking further into the complaints, and has sought further information from Mr Kang."
Screenshots of messages sent by Kang's campaign manager have also been given to the commission.
Wetex, a Malaysian-Chinese beekeeper and former pharmacist, has since been barred by his party from using the app.
Kang told the Herald he was not able to comment as the matter was before the party's lawyers.
But he maintained he had done nothing wrong and the complaints were "a set up".
Party president Tukoroirangi Morgan said the party was taking the allegations very seriously.
"Our party is working with the Electoral Commission and we have asked Mr Kang to stop using WeChat until we've finished looking into the matter," Morgan said.
Kang was last month announced as the first Asian candidate for the Maori Party, saying he put his hand up to stand in the election so he could be a voice of migrants.
He's Malaysian-Chinese and speaks three different Chinese dialects and understands Malay.
He considered running for the National Party but then decided on the Maori Party, Kang said at the time.
"I have always felt within my blood that I have a good link to tangata whenua," he said last month. "I want to show New Zealand that we can all live here peacefully together, and we're all just New Zealanders."
It was a sentiment echoed by Morgan, who last month said Maori and Asians shared the same whakapapa and genealogies.
"We are aligned in our cultural values, our vowel pronunciation is very similar," he said.
The Electoral Act 1993 forbids bribes or treats in exchange for votes - that includes money and positions, as well as food, drink, entertainment or any kind of provision.