Gardai from the Organised Crime Unit (OCU) are constantly monitoring the activities of a west Dublin criminal who is suspected of involvement in up to 10 tiger kidnappings.
The Herald has learned that the mobster, who is aged in his mid 30s, was recently stopped by specialist detectives while he and a close associate were carrying out surveillance on a target in the Blanchardstown area of the capital.
Suspicious items were found in the vehicle the criminals were travelling in during a late night armed garda search, but there was not enough evidence to charge either of them with any criminal offence.
The secretive OCU operation against the criminal is continuing, according to sources.
"This individual is being watched extremely closely by specialist gardai who are using all technological means available to them to make sure that he does not strike again," a source said.
"The man who was with the tiger kidnappings planner is from the Hartstown area and he is also extremely well-known to gardai for involvement in this type of organised crime."
The OCU operation comes against a backdrop of a major decrease in tiger kidnappings and cash-in-transit robberies this year, with gardai having major successes in getting some of the main players locked up.
These include a dangerous gang boss who is suspected of being involved in a tiger kidnapping at Bayside post office in north Dublin in September.
He was arrested and charged with other offences last month and is currently in custody.
The Bayside incident, in which three people were tied up and held at gunpoint during a terrifying 10-hour ordeal, also involved gardai firing shots at the gang, and is the only such crime recorded in the last several months.
There has also been a significant decrease in cash-in-transit robberies, but sources say the need for the continuing monitoring of the west Dublin criminal mastermind shows that "these thugs have not gone away at all".
Among the small number of cash-in-transit robberies that gardai have had to deal with in recent months are one in the Mulhuddart area on October 31 and a €20,000 heist at a post office in Dolphin's Barn on September 17.
A cash delivery at the post office in Omeath, Co Louth, was also targeted on August 20 and €14,000 was stolen, but all this cash which was covered in dye was later recovered following a joint operation by gardai and the PSNI.
Security companies are now using exploding glue which mixes with dye in cash boxes in an attempt to foil cash-in-transit robberies.
This measure has also put off gangsters involved in the crimes.
The technology is the latest to be used by the security industry.
It works by releasing glue inside the cashbox when someone tries to open it.
Should the person try to recover the notes, the process will cause them to de-laminate, rendering the bank notes in the cashbox completely unusable .
The glue also contains existing technologies in dye, which stains the notes, and SmartWater - a forensic solution invisible to the naked eye but detectable under UV light which contaminates the person who has breached the cashbox for up to six months.