The Criminal Assets Bureau (CAB) has confiscated 84 cars seized from a dealership in Co Tipperary last year and €153,000 from a company bank account in Co Kerry.
The assets, which the High Court has found to be the proceeds of crime, were seized last September from a company called Autology run by the Khan family from Lithuania.
Agne Khan is listed as the 100% shareholder of the company and controlled its bank account along with her brother-in-law Jawad Khan.
His wife, Simona, was company secretary while Agne is married to Khuram Khan.
The vehicles seized, which include Range Rovers, BMWs, Audis, Volvos and Skodas as well as flatbed trucks, have been sold by CAB.
The High Court found that there was cogent evidence that the Khans and their associates were involved in "complicated mandate frauds", the proceeds of which were used to fund businesses in Ireland and England.
Mr Justice Alexander Owens said the proceeds of fraud were laundered into businesses to buy cars from British auctions which were then sold through second-hand car dealers controlled by the Khans in England and Ireland.
In ten linked frauds investigated by West Midlands Police over £1.3m was stolen, while another £900,000 was stolen in another series of frauds involving the National Health Service.
West Midlands Police also seized 90 cars in the UK in conjunction with the CAB raids in Ireland.
Autology traded from Unit 1, Ballywilliam, Carrigatogher, Nenagh in Co Tipperary.
The company began operating in used cars under the name Autopace in May 2019 and opened the bank account in Tralee.
The commercial unit it traded out of in Ballywilliam is owned by another Khan-controlled company.
SJK previously traded as a car dealer from the same premises and sold vehicles sourced by the Khans and their associates in England.
It ceased trading in December 2018 after the Revenue Commissioners found tax irregularities.
The High Court found the Khans walked away from SJK taking with them trading proceeds and leaving behind revenue liabilities of €623,000.
Money, it said, was sent by "a roundabout route" using accounts of friends and relations of the Khans. It was used to buy cars. Money then came back into Ireland into accounts associated with the Khan-controlled businesses here and was withdrawn.
The High Court found that the frauds have enriched the Khan by over £3.5m.
Khuram Khan was convicted in England of mortgage fraud offences involving almost £8m while Agne Khan was also involved and was sentenced to 18 months in prison but fled England in 2009, returning five years later.
The Khans now live in the UK.