Sinn Féin has received a further £800,000 from the will of an English man who died in Wales in 2018.
Billy Hampton has now left the party almost £3 million.
The former mechanic, who was not married and had no children, left some money to friends and acquaintances, but the main beneficiary of the will was the Irish republican party.
The money came in instalments of £1.5 million announced in September 2019, followed by about £500,000 later that year.
It is the largest donation given to a political party in Northern Ireland.
In 2019, Sinn Féin president Mary-Lou McDonald paid tribute to Mr Hampton as a “rebel with a cause”.
His ashes were buried in west Belfast.
In the most recent round of figures on political party donations published by the Electoral Commission, the latest £800,000 in cash is recorded as having been accepted by Sinn Féin on February 10th.
In total, six political parties registered in Northern Ireland reported accepting £1,070,999 in donations and public funds in the first quarter of 2021.
Sinn Féin accepted £880,295 while the Alliance Party accepted £29,564 in donations, the DUP accepted £78,115, the Green Party accepted £12,173, the SDLP accepted £47,958 and the UUP accepted £22,894.
Cahir Hughes, Head of the Electoral Commission in Northern Ireland, said the data was published to give voters important information on how parties in Northern Ireland are being funded, in order to enhance public confidence and trust in democratic processes.
