A difficult week for Northern Territory Labor has worsened after it was revealed Manuel Brown had his driver's licence suspended for three months last year after repeatedly speeding.

The Arafura MLA confirmed on Wednesday that his licence was suspended in October last year after he accrued 12 demerit points while driving his taxpayer-funded vehicle.

First reported by the NT Independent, the suspension was not publicly disclosed at the time by Opposition Leader Selena Uibo.

Mr Brown, who holds several shadow portfolios, was first elected at the 2023 Arafura by-election before retaining the seat during Labor's devastating 2024 election defeat.

In a statement, he apologised for falling short of the standard expected of a public official.

"Late last year my licence was suspended for three months after accumulating demerit points," Mr Brown said.

"That was my responsibility, and I should have done better."

Ms Uibo said Mr Brown had informed her of the suspension when it occurred, but acknowledged the matter should have been made public.

"I accept that whilst there was no traffic incident involved in the infringement, this should have been acknowledged publicly due to the matter involving an elected member of my team," she said in a statement reported by NT News.

"During the suspension, Manuel did not drive, his work continued through existing office arrangements, and there was no special taxpayer-funded driver or vehicle arrangement."

Previous driving conviction

It is not the first time Mr Brown's driving history has attracted scrutiny.

During the 2023 Arafura by-election campaign, it emerged he had previously been convicted of driving without due care over a 2009 crash in Katherine that resulted in the death of a 62-year-old woman.

After the initial charges of driving a motor vehicle causing harm or death and not stopping at a stop sign intersection were dropped, he was given a 12-month good behaviour bond.

Neither Mr Brown or NT Labor initially disclosed the conviction, but when it was made public, he told NT News: "Since that day I've completed my (social science) studies and dedicated my life to bettering the lives of those people who need it most, through my work in a number of government agencies, community service providers and Aboriginal organisations.

"But I cannot let my demons that have stayed with me from that day continue to dictate my future, or what I'm capable of achieving for my people."

Leadership turmoil and bullying allegations

The revelations are the latest setback for NT Labor, which has spent the past week dealing with an internal leadership shake-up and allegations of bullying within Ms Uibo's office.

The complaints are understood to centre on cultural safety concerns raised by Indigenous staff, including allegations involving a senior member of Ms Uibo's office and the opposition leader's handling of the reports.

On Tuesday, Ms Uibo — Australia's first female Indigenous leader of a political party — defended the culture of her office and said complaints were taken seriously.

"My focus is on ensuring appropriate processes are followed, supporting the wellbeing of those involved, and identifying any improvements that can strengthen our workplace culture," she said.

The allegations became public after Ms Uibo announced that the deputy leadership position was vacant, with Daly MLA Dheran Young replaced by Ed Smelt.

It is understood Mr Smelt won the deputy leadership ballot — having only been elected in March — by three votes to two after Mr Brown, who is aligned with Labor's Left faction alongside Mr Young and Chansey Paech, voted with the unaligned Ms Uibo and Mr Smelt.

After losing the deputy leadership, Mr Young said he was disappointed by the decision and would relinquish all 10 of his shadow portfolios, including Aboriginal affairs.

"It is a decision I wish has not occurred," he wrote on social media.

"I have always been clear about the direction I believe our party needs to take, the values we must stand for, and the reforms needed to make Labor stronger."