Sinn Féin MP Martin McGuinness was reportedly barred from fundraising in the United States this week despite the completion of IRA decommissioning.
Under US government rules, foreign politicians must seek permission to raise funds from US donors ahead of each visit to the country.
Reports this morning said Mr McGuinness was denied this permission during a visit to US this week as a result of an informal ban imposed after the Robert McCartney killing.
The move has reportedly worried Sinn Féin's Irish-American supporters in advance of next month's Friends of Sinn Féin fundraiser, which usually nets up to $400,000 for the party.