The Maori Language Commission, Te Taura Whiri i te Reo Māori, is demanding an apology from Maori Television over the broadcast of a report alleging the mismanagement of taxpayer funds.
Maori Television says it is reviewing the report, which ran on its Te Kaea programme on 17 August.
"The programme included a number of allegations which are false and defamatory, including allegations of mismanagement, misappropriation of public money and greed," the commission says in a statement.
The commission denies the claims, saying Te Kaea has no evidence to justify them.
It says the allegations are highly damaging to its reputation and to the reputation of its chief executive, Glenis Philip Barbara, and legal action might follow if an acceptable apology is not broadcast.
Maori Television says it cannot comment further until senior management have finished the review into the report and how it was constructed.