Sinn Féin has received another large donation of £800,000 from the same deceased donor who had already left the party more than £2m.
The party received the first portion of the money in 2019 in the will of 82-year-old Englishman, Billy Hampton.
Mr Hampton, a former market trader, died in 2018 in Wales.
The £2.9m windfall to date is the largest known donation to a political party in Northern Ireland from a single donor.
The first tranche of the money – £1.5m – was announced in September 2019, followed by about £500,000 later that year.
According to the Electoral Commission, which on Thursday published political party donations for the first three months of 2021, the extra £800,000 in cash was accepted on 10 February.
When details of Mr Hampton’s donations emerged in 2019, questions arose about his mental health.
It is believed he had a psychiatric history. Many years ago, he spent time in a psychiatric unit.
His father, Tim Hampton, was a wealthy businessman who had significant commercial interests in the village of Fenstanton in Cambridgeshire.
According to Billy Hampton’s friends, he was unhappy during his life because he could not access all the inheritance he felt he was entitled in a single lump sum.
As a result, friend Dave Morton said Mr Hampton decided to leave his own fortune to Sinn Féin “out of spite” and “to say ‘up you’ to the British establishment”.
Up until his death, he had led a nomadic existence living in a camper van and travelling around the UK, Europe and further afield.
Mr Hampton made his will in 1997 when he was living in a caravan in County Cavan.
According to a copy of it, the executors and trustees were former IRA chief-of-staff Joe Cahill and another republican called Dessie Mackin.
In one letter written in France in 2001, Mr Hampton wrote: “I am much less paranoid than normal, and do not suffer from a persecution complex at all here in France.”
In the same letter, written four years after he wrote his will, he said: “Sinn Féin will not speak to me now for security reasons.”
The party has erected a memorial stone in his honour at a cemetery in Hannahstown, County Antrim.
The inscription reads: “True friend of Ireland. Remembered by his true friends and comrades in Sinn Féin.”
Separately, the Alliance Party received £12,500 in donations in the same period, according to the Electoral Commission.
Northern Ireland’s six political parties registered reported accepting a total of £1,070,999 in donations and public funds in the first quarter of 2021.