The pair, who ran the Italian Wine Company in Neasden, lied about the quantity of imports and sales figures to evade excise duty and VAT.
In a combined investigation, HMRC and the Italian Customs Authority raided the pair’s Neasden warehouse in April 2013, seizing more than 70,000 litres of duty-free wine and £350,000 in cash.
At the trial it was found that between 2008 and 2013 the pair falsified documents and re-used import documents to smuggle wine from Italy.
They distributed the smuggled wine, before laundering the money through a string of bank accounts.
Mazzarello, who absconded during the trail, was sentenced in absentia to 14 years imprisonment on 30 June. For her part, Mbadugha got three and a half years imprisonment on 14 July.
“Mazzarello and Mbadugha thought they had developed the perfect scheme to divert millions of pounds from public finances,” said Simon York, director, fraud investigation service, HMRC.
“They were stealing from the taxpayer and undercutting legitimate traders.
“They were wrong and we are working to reclaim any money they made from their crimes,” he added.
The HMRC has been increasingly calling upon foreign governments for help in tax probes.
Last week, a Freedom of Information request showed that the Revenue received 24% more requests for assistance from overseas governments with probes into taxpayers from overseas jurisdictions last year.