Detectives were in contact with the Director of Public Prosecutions last night as to whether or not the man should be charged or released.
The cash, up to €12,000 in total, had been removed from a property store at a station on the southside of Dublin sometime at the start of the year.
The individual arrested in Dublin City was detained under section 4 of the Criminal Justice Act.
A criminal investigation was set up last April after an initial examination concluded that the money was not simply misplaced, but was most likely taken.
After conducting their inquiries, detectives moved on their suspect and made the arrest yesterday morning in the city centre.
Meanwhile, gardaí are questioning a man after he attempted two carjackings and accosted an elderly woman in west Dublin.
The incident happened yesterday afternoon when a man, described as a well-known petty criminal, managed to get keys from two cars and attempted to carjack, but was unable to find the vehicles.
At one stage he accosted an elderly woman, but her son stopped him and restrained him until local gardaí arrived. He was detained under Section 4 of the Criminal Justice Act.
Separately, gardaí and Crimestoppers have asked people with information in relation to the murder of a Polish man to come forward.
The body of Michal Kurek, aged 33, was found dumped on a local road at Ballyboughal, north county Dublin, on August 4 last. He had suffered multiple stab wounds. Originally from Dziewin in Poland, he had lived mainly in Ireland since 2010.
He was recently homeless and frequented the Ongar area of north west Dublin.
Any information to Balbriggan Garda Station on 01 6664500; Crimestoppers 1800 25 00 25.