Isis, or Islamic State, has been taking over cities in Syria and Iraq and conducting high-profile beheadings of hostages, as it tries to establish an Islamic caliphate that traverses the border between the two countries.
The Government last month raised New Zealand's national threat level in response to risk posed by the terrorist group.
Mr Kireka-Whaanga who said he wasn't a violent person, pledged his support for Islamic State, saying it would bring down Western civilisation and true Muslims were behind Islamic State.
He said he wanted to travel with his family to Syria, where one of his brothers already lived.
Watch: PM: Isis fight - NZ won't be a target
His ex-wife, Hastings' Jameela Hawkin, who is also a "very devout" Maori Muslim, said she did not consider her former husband a leader of the group. The association had up to 150 members in Hawkes Bay and there were about 2000 Muslims in the region overall.
"We do not support what he's saying. Isis has nothing to do with Islam. Islam is a religion that promotes peace - we don't support anything Isis are doing."
She said Mr Kireka-Whaanga was using Facebook in an attempt to spread his beliefs. "I know on Facebook he's actively posting information."
He has 909 friends on Facebook. A status update on his page says his account was disabled for 60 days this year because of "anti-National Party quips".
As a result of his behaviour, Ms Hawkin said police had visited "several members" of the region's Muslim community and Mr Kireka-Whaanga "is being monitored".
"There are a lot of really upset members of the Hawkes Bay Muslim community."
She said Hawkes Bay residents were particularly tolerant of Islam. "We get the odd comment, but not what people are experiencing in Australia, or in Hamilton or Auckland."
But despite an expected backlash over Mr Kireka-Whaanga's comments to media this week, she didn't believe he should be excluded by the group. "We don't believe in dividing the community." Now 40 years old, Mr Kireka-Whaanga had converted to Islam from his Mormon faith at the age of 22.
The twin cities' MPs were yesterday condemning Mr Kireka-Whaanga's support for Islamic State.
Napier MP Stuart Nash said given the current situation in the Middle East, Mr Kireka-Whaanga should be taken seriously.
"In my view there is no place for this guy in our society whatsoever.
"The Isis brand is one based on hate, terror and subjugation - not what we practise in New Zealand, and it is not practiced by the majority of Muslims."
Watch: Decision on Isis commitment soon - Key
Tukituki MP Craig Foss said: "We are a very tolerant place and people are certainly entitled to their views but for anyone to support the absolutely horrific atrocities we've witnessed in the media that are going on [in the Middle East] is beyond belief.
"Regardless of race, religion or creed the barbaric actions happening up there are absolutely wrong, full stop."
The Herald interviewed Mr Kireka-Whaanga 10 years ago when he claimed to be regularly visiting prisons, as part of a project to convert inmates to Islam.
He is understood to have been since banned from visiting prisons.
Police declined to comment about Mr Kireka-Whaanga yesterday.
Mr Kireka-Whaanga could not be contacted for comment.
