The fight has been organised by Daniel Kinahan
The 46-year-old Dublin man has been named in the High Court as a senior figure in the Kinahan organised crime gang.
The Sunday World reports the threats, by a rival crime gang, aim to derail Kinahan's efforts as a boxing promoter.
Taoiseach Leo Varadkar previously said broadcasters and sporting groups should have "nothing to do" with the upcoming fight between Tyson Fury and Anthony Joshua, which he has organised.
Sunday World Crime Correspondent Nicola Tallant says the high-level attention's the last thing Kinahan needs:
