SINN Fein is being bankrolled with donations from American companies that have been embroiled in racism, discrimination and embezzlement scandals.
The revelation comes as Gerry Adams is currently on a fund-raising trip to the US as pressure mounts on him over accusations levelled at him regarding the murder of Jean McConville.
The daughter of the murdered Belfast mother of 10, the most notorious case of the Disappeared, believes gardai must reopen the case and interview Mr Adams.
The Sinn Fein president escaped the spotlight this week by travelling to New York to attend a party fundraiser.
Mr Adams' party is sending tens of thousands of US dollars back to Ireland for campaigning.
The party is ramping up its fundraising drive in the US as it prepares to pump huge sums into next year's local and European elections.
Newly-filed documents expose the massive war chest being built by Sinn Fein across the Atlantic.
An investigation by the Irish Independent revealed:
* The party took in a staggering $392,000 (£245,000) during the six-month period up until May of this year.
* Almost $50,000 (£31,000) was used to pay printing expenses in Northern Ireland and to purchase a vehicle.
* Sinn Fein has accepted donations from bodies that have been embroiled in racism, embezzlement and corruption scandals.
* The party is receiving individual sums of up to $20,000 (£12,500) and has even been left portions of dead people's estates.
The cash pile of Sinn Fein in the US lies in five bank accounts based in New York.
The accounts are operated by the Friends of Sinn Fein organisation (FOSF), known internally as the party's fundraising wing.
FOSF is headed by Jim Cullen – a former US army general whose parents are Irish.
Documents filed with the US Department of Justice show that more than $392,000 was received through 280 individual donations between November and May. This equates to a donation of almost €1,600 (£1,000) every day.