The High Court case was brought in the names of two men – Florin Rostas, a Roma gypsy, and John Maughan.
Their lawyers argued successfully that under the Act the gardai must establish that they did not have a licence to solicit money from the public.
Both had been charged under Section 2 of the 2011 Act, which prohibits begging that involves harassment or obstruction.
The 2011 Act defines begging as requesting or soliciting money "other than in accordance with a licence, permit or authorisation".
The High Court found that the gardai were obliged "to establish a prima facie case that the begging took place without legal authorisation".
It added: "Once this is established the burden of proof is transferred to the accused to establish a reasonable doubt as to the legality of the begging.
"It is a matter for the trial judge to decide if a prima facie case has been established."
The High Court case succeeded in January last year but it took a further year for the bulk of the begging convictions – it is understood there were around 200 convictions – to begin being struck out on appeal.
Once this began the beggars began returning to the streets.