Wealthy dissident smuggler Aidan Grew is at the centre of a £215m money laundering probe.
Security sources have linked the convicted IRA bomber turned millionaire crime boss to the cross-border scam which led to eight arrests and raids on properties in Belfast, Ballymena, Banbridge, Newry and Omagh.
Following the searches, the PSNI confirmed the investigation is the second biggest money laundering operation ever uncovered in the UK.
At the heart of the scam is 63-year-old Grew from Blackwater, Co Armagh, who also served a jail sentence for evading duty on millions of illegal cigarettes smuggled into Northern Ireland from China.
He is suspected of using middle-men to set up front companies through which his millions of pounds of dirty cash is laundered.
"Grew is all over this investigation," a security source told Sunday Life. "He is too high profile to have any of the money he makes from smuggling pass through his own hands, so he uses middle-men to pay others to set up front companies to do it.
"He has been paying another dissident republican from Co Tyrone to find people to become directors of these front companies."
At a press conference last week, the PSNI said the £215m money laundering probe was not connected to any paramilitary organisation.
That is accurate in the sense that Grew is no longer affiliated to any republican grouping having ditched the Real IRA after it joined with other republican gangs to form the New IRA.
Our source added: "Grew is still well thought of by republicans of all shades in Armagh and Tyrone, but he doesn't bother with politics any longer, for him it's all about the money."
Cops probing the major £215m money laundering racket are directly linking Grew to some of the 50 front companies the National Crime Agency (NCA) believes are being used to launder millions in criminal proceeds.
One of the properties searched last week has over a dozen firms registered to its address, with most never having filed accounts or being quickly dissolved after they were set up. Many have directors in common and are linked to other front businesses in the Republic of Ireland.
Police say the money laundering began in 2011, with cash being deposited in thousands of bank accounts across the UK. It is then filtered out of the country through foreign exchange companies.
In 2008 Grew admitted evading duty on almost five million smuggled cigarettes and was sentenced to three years imprisonment suspended for two years providing he paid £500,000 in unpaid duty. He failed to pay-up and was returned to jail.
His sister Patricia O'Neill showed up at the gates of Maghaberry Prison with £500,000 in cash to try and secure his release.
A hold-all containing the money was seized by detectives due to suspicions it was the proceeds of crime and should be taken as evidence of alleged money laundering. Aiden Grew applied to the High Court to have it returned but the judges held that police seizure of the cash was lawful.
Last summer, he was back in the headlines when his glamorous sister Donna Grew was subject to an investigation by the NCA over money laundering and cigarette smuggling.
The London-based 53-year-old was hit with an Unexplained Wealth Order (UWO) and had £3.2million worth of assets frozen.
Teacher turned estate agent Donna lived in an expensive apartment just off the King's Road in west London.
Raids on 15 properties across Northern Ireland last week saw seven people arrested on suspicion of laundering international criminal assets.
The searches were carried out as part of an investigation by the PSNI in cooperation with Garda Economic Crime Bureau (ECB), Criminal Assets Bureau (CAB), National Crime Agency (NCA), United Kingdom Financial Investigation Unit (UKFIU) and Her Majesty's Revenue and Customs (HMRC).
All seven were eventually released on bail pending further enquiries.