Kireka-Whaanga, who lives in Hastings, works at Fresh Meats NZ in Napier.
Manager of Fresh Meats NZ, Alistair Martin, said the videos were unauthorised and not approved by the company.
"As these have now been brought to our attention we will address this matter with Mr Kireka-Whaanga directly.
"Conduct issues are a confidential matter between employee and employer, it would therefore be inappropriate to disclose anything further at this time."
SAFE Veterinary Professor Andrew Knight said the footage was alarming, and at least one of the sheep appeared to be conscious as it has its throat cut.
"I'm really disturbed about seeing the sheep actually move after their throats have been cut and after they 've been hung up in the shacking device because the movement of the sheep raises doubt about whether these sheep are actually unconscious as they are supposed to be."
He said animals were stunned before they had their throats slit and it was important that the correct voltage was used so they were unconscious but not killed by it as that was against Halal requirements and degraded the meat quality.
Knight said if the stunning was not at the right level then the animals may be awake through the killing process.
"This is always the case for a certain minority of animals and that is a terrible thing when you consider what happens to the animals afterwards - chickens going through [a] scalding bath, sheep and other livestock being hung upside down from shackles."
Knight said MPI should launch an investigation.
He said the Ministry needed to inspect the stunning equipment and make sure it was adequately maintained, and check the time period between stunning and slaughtering which should be between 10 and 20 seconds.
In 2014, NZME reported that Kireka-Whaanga was calling on "souljahs of Allah" to make their way to Hastings and join him in forming the "Islamic State of Aotearoa".
The group had formerly been known as the Aotearoa Maori Muslim Association.
Mr Kireka-Whaanga had previously pledged his support for Islamic State on social media, saying it would bring down Western civilisation, and true Muslims were behind Islamic State.
