Sinn Féin: 'Nothing to see' in William E Hampton donation
Michelle O'Neill has said there is "nothing to see here" after Sinn Féin was given £1.5m.
It is understood to be the largest ever known donation to a Northern Ireland political party.
The money was given to Sinn Féin as a bequest by William E Hampton, a former motor mechanic and driver, who died in Pembrokeshire, Wales.
The TUV leader Jim Allister has called for the National Crime Agency to investigate the donation.
But Sinn Féin has said it has complied with all Electoral Commission rules and regulations.
Speaking on the BBC's Talkback programme, Ms O'Neill, the party's vice-president, said she had never met Mr Hampton but welcomed his donation.
She said it would "help the party to build and lead the challenge towards a new and agreed Ireland".
However, she rejected suggestions that the party should provide more transparency about the nature of the donation.
"I understand it's a juicy story but there's nothing to see here," she said.
"A lot of people are trying to make something out of a story that isn't there.
"It's a significant donation - the party leadership will decide how it's used."
In March 2018, legislation was passed at Westminster to allow donations and loans of more than £7,500 to parties in Northern Ireland to be revealed.
However, the law only covers donations made to parties from 1 July 2017 onwards.