Almost 140 targets in the Shannonside Northern Sound region were under investigation by the Criminal Assets Bureau last year.
Figures up to December reveal 66 targets across the Roscommon-Longford Garda Division were being investigated by CAB.
This figure is significantly higher than the other garda division in the Shannonside region, with 14 targets under CAB investigation in Sligo-Leitrim.
In the Northern Sound region, 56 targets were under investigation across the Cavan-Monaghan division.
CAB's annual report for 2020 shows it dealt with over 1,700 targets last year, up nearly 400 from 2019.
The CAB also managed to return over €4.2 million to the Exchequer, and returned over €5 million to the Nigerian Government following the signing of a Memorandum of Understanding in October 2020.