Criminal gangs could be extorting millions of pounds from thousands of small businesses in Northern Ireland, according to the Police Service of Northern Ireland.

Under-threat traders, often in working-class loyalist or republican areas, are the least able to pay illegal taxes imposed by paramilitary thugs, PSNI Detective Superintendent Bobby Singleton said.

Many do not report the intimidation, which is supporting lavish crime lord lifestyles.

Det Supt Singleton said: "Those operating in working-class communities across the country (are) struggling to make ends meet and having to pay this totally illegal taxation to paramilitary thugs."

Extortion is under-reported but, based on intelligence, he said it was an extensive problem across Northern Ireland.

Organised criminals are targeting legitimate businesses in working-class areas as well as drug dealers seeking the "right" to operate in the areas they control, he added.

Det Supt Singleton said: "It is a key point of how paramilitaries generate their funds and support their lifestyles."

He said the extortion was worth thousands of pounds, if not millions.

Around 100 organised crime gangs are operating in Northern Ireland - a quarter with links to paramilitaries - and most deal in the lucrative and low-risk drugs trade, Det Supt Singleton added.

Last year, 183 organised crime groups were dismantled, frustrated or disrupted, the head of the Organised Crime Task Force Anthony Harbinson said.

About 10-15% of organised crime groups have a foreign dimension, Det Supt Singleton said.

Unexplained wealth orders cracking down on high-rolling criminals are used in Britain but have not yet been introduced in Northern Ireland because Stormont power-sharing is stalled.

Officials still have the ability to confiscate criminal money; £1.9 million in criminal assets was recovered last year with half returned to law enforcement agencies, prosecutors and the courts.

The remainder was allocated to initiatives to reduce crime and the fear of crime.

Since the establishment of the PSNI's Asset Confiscation and Enforcement Team last year, there has been a 150% rise in the number of PSNI restraints being put in place and a 50% increase in the number of confiscation orders granted by the courts.