The returns show the National Party was also late to disclose donations from real estate bigwig Garth Barfoot, a regular donor.
Barfoot donated $15,000 in May, a further $10,000 in October and another $10,000 on November 11. The November donation tipped Barfoot over the $30,000 threshold, but the donations were not disclosed by the party until March 31.
The Electoral Commission said it had asked for an explanation from the National Party and was still assessing the matter.
It did not automatically refer all late donations to the police, but considered issues such as the party's past record and the timeframes involved.
A spokesman for the National Party declined to set out the reasons for the late disclosure:
"We keep in regular contact with the Electoral Commission, particularly in regard to supplying information and explanations on the disclosure of donations."
Māori Party President Che Wilson put the late disclosure of donations down to "rookie" mistakes, saying the party executive had misinterpreted the law.
"When we did our clean-up of everything, we realised we needed to report that so we made contact with the Electoral Commission straight away."
Wilson said Tamihere paid for some party costs out of his own pocket and the party had not realised it was supposed to treat those as donations.
Tamihere's donations are a long list of smallish amounts, other than an $18,000 sum on August 31.
Both Wilson and party secretary Rose Waetford were in their first elections in the role, and the party was run by volunteers.
"Definitely rookies. It was the first time for us all to manage a campaign."
"I'm shattered that as a voluntary party we've got to this pothole on the journey. So we need to tidy it up."
Asked why the $120,000 donation from Aotearoa Te Kahu Limited was not disclosed for almost a year after it was received on July 2 last year, Wilson said as soon as the party realised, it had gone to the Electoral Commission to disclose it.
Under electoral laws, political parties must disclose donations of more than $30,000 within 10 working days.
That also applies to a series of smaller donations from the same person which add up to $30,000 in a year.
If a party secretary is convicted of failing to file donation returns according to the law, the penalty is as high as $100,000 fine, or up to two years' imprisonment.
The three donations are now listed in the Electoral Commission's returns.
The Electoral Commission has also referred an unnamed candidate to the police for "election expenditure and alleged non-disclosure of candidate donations".
