PSNI Chief Constable Sir Hugh Orde has said dissident Republican organisations continue to represent a real threat to the success of the peace process on both sides of the Border.
Speaking at a cross-Border security forces seminar in Enfield, Co Meath, yesterday, Sir Hugh said the Real IRA, Continuity IRA and INLA remained organisations of concern for the PSNI and Garda.
The successes of policing operations in the North and South in recent times proved that these groups were still active.
"In the last two months, we've had a firearms find and a 400lb bomb, which was 125 per cent the size of the Omagh bomb," Sir Hugh said.
He also pointed to a security operation in Craigavon, south Armagh, last week in which nine suspected dissident republicans were arrested as police searched for weapons and explosives.
"So the notion that we can forget about that threat is simply a flawed one. They are out of date, they are behind the times. They do not have the support of the community; they seem to have lost the plot. They are disorganised and discredited but they are nonetheless dangerous."
Minister for Justice Brian Lenihan said the Government shared Sir Hugh's concerns.
"Of course, anyone who hasn't subscribed to the peace process on this island is a danger and a threat and has to be dealt with. We're working very closely with the authorities in Northern Ireland to make sure that that threat is kept to a minimum."
Mr Lenihan said he did not believe crime gangs were made up of "master criminals" who "through dint of their genius" continued to evade the best efforts of the PSNI and Garda.
"Week in week out you are having success, often unsung, against the people involved," he told a delegation of police, customs and government officials from both sides of the Border.
The rest of the two-day conference and workshops are being held behind closed doors.
Deputy Garda Commissioner and incoming Garda commissioner Fachtna Murphy said while traditional cross-Border crime such as laundered fuel and cigarette smuggling remained a problem, he believed the gangs were engaging in more modern and complex forms of criminality. These included drug dealing, immigration crime, fraud, internet crime, tiger kidnappings and human trafficking. While human trafficking had received prominent media coverage recently, its extent in the Republic remained unknown.
"The increased level of migration would provide opportunities for people. But the jury is still out, so to speak, on the levels." He told delegates the Border would continue to represent an opportunity for gangs engaged in organised crime.
Northern Ireland policing and justice Minister Paul Goggins said he believed the police forces and governments North and South now had an "effective and active partnership". Cases over the past year underlined the success of the relationships. These included an £18 million VAT fraud settled jointly by the Criminal Assets Bureau and Assets Recovery Agency. An illegal and dangerous gas bottling plant in Armagh was another example.
Other success included recent arrests in cases where attempts had been made to extort money from construction industry workers and in relation to the seizure of 6.3 million cigarettes.
Responding to comments by the Garda Representative Association (GRA) that arming uniformed gardaí should no longer be considered a "taboo", Mr Lenihan said there were no plans to arm uniform members.