« Reply #1 on: Thursday 27 August 20 13:00 BST (UK) »
Your man is in the Dublin Metropolitan Police Prisoners Books, available on findmypast
The prisoner books are also available on this site for free:
https://digital.ucd.ie/view/ucdlib:4394815 July 1915 spreads over two pages. He is the top line on the second page.
I don't think he was imprisoned, just escorted back.
Coffey, Cummins [Rathfalla, Tipperary], Cummins [Skirke, Laois], Curran, Dillon [Clare], Fogarty [Garran, Laois/Tipp], Hughes, Keshan (Keeshan), Loughman [Harristown and Killadooley, Laois], Mallon [Armagh], Malone, Markham [Caherkine, Clare], McKeon(e) [Sligo/Kilkenny/Waterford], McNamara, Meagher, Prescott [Kilkenny/Waterford/Wexford?], Rafferty, Ryan, Sullivan, Tobin
GEDMatch: T665306 tested with Family Tree DNA and also with ancestry
GEDCOM file: 1980344