A report into allegations against Sam Uffindell has exonerated the new Tauranga MP.

National Party leader Christopher Luxon received the report by KC Maria Dew into historical allegations of bullying by Uffindell late last week. The report itself is unlikely to be released, but what decisions were made were revealed at a press conference today with Luxon, Uffindell and National Party President Sylvia Wood.

Luxon had asked Dew to look into allegations about Uffindell's behaviour at university and any further incidents that were brought to her attention.

Wood said the investigation took place between August 15 and September 15 but they would not be releasing details of the report.

Uffindell had said he was a bully, harmed people and apologised.

Fourteen people were interviewed in the investigation and there were written statements.

Dew's investigation did not substantiate any allegations of bullying outside of Uffindell's time at King's College in Auckland.

Regarding the Dunedin flat incident, Dew concluded the event was not as reported after an allegation was made to RNZ by one of Uffindell's former university flatmates.

However, the incident did cause the woman involved harm.

Nobody else came forward who considered themselves a victim of Uffindell's behaviour, but Luxon said he wanted to acknowledge people hurt and harmed by Uffindell's behaviour.

Luxon said he was disturbed by the alleged Dunedin flat incident.

National leader Christopher Luxon with MP for Tauranga Sam Uffindell. Photo / Mark Mitchell

The National Party caucus decided today to reinstate Uffindell. Luxon said he believed in second chances and forgiveness.

Uffindell, meanwhile, said he welcomed the findings.

He said he was "genuinely shocked" at the allegation from Dunedin and there was a "genuine breakdown" in the flatting relationship.

Uffindell said he had not spoken to the woman who made the allegation against him since their flat fallout in 2003.

Asked if he was happy to have a bully in the party, Luxon said he did not believe they had one.

Uffindell said he did have a stomach for politics though the past few weeks had been "challenging".

If Luxon had decided to stand Uffindell down on the basis of that report, it could have resulted in another byelection in Tauranga - unless Uffindell decides to stay on as an independent MP.

Uffindell has been away from Parliament since he was stood down from caucus on August 9 after details surfaced of allegations of bullying and intimidatory behaviour in his youth.

Over the weekend, Uffindell was at a Women's Expo in Tauranga - National's central North Island regional chair Andrew von Dadelszen posted a photo of Uffindell holding a National Party rosette.

In response to a commenter, von Dadelszen said "Sam is in excellent heart… itching to get back to work, supporting Tauranga in Wellington."

Luxon had initially stood by Uffindell after Stuff revealed in early August that Uffindell had been asked to leave Auckland boarding school King's College for physically beating a Year 9 (third form) student while Uffindell was Year 11 (fifth form) in 1999.

However, he ordered the report and stood Uffindell down after the further allegation to RNZ by one of Uffindell's former university flatmates, including that he had once banged on her door and shouted at her - and she had fled through her window, and then moved out of the flat.

Uffindell has rejected that allegation, but admitted he had been a bully at school.

He claimed he was now a different person.

Uffindell had disclosed the incident at King's College during the selection process for the Tauranga byelection.

However, that information was not passed on by the selection panel to either Luxon or the delegates voting in the selection.

It later emerged that MP Todd McClay, who chaired National's byelection campaign, had advised one of Luxon's staff, but the staffer did not tell Luxon.

Luxon has previously said that he should have been told about it and that the party's delegates and the public should also have been told.

National Party president Sylvia Wood has previously said the selection process was run in accordance with the party's rules, but admitted it was now clear the process needed to be improved.

The party overhauled its selection processes after 2020 following a bruising election defeat, and MPs leaving under a cloud of scandal during the previous two terms.