Mr Greig, who conned more than 140 clients, telling investors he would put their money into a guaranteed short term deposit scheme.

The 66-year-old told clients of Midas Financial Solutions in Aberdeen he had exclusive access to high-interest accounts with RBS.

In reality, Mr Greig was using the money to invest in property, a classic car business and to treat himself to trips.

Some investors did receive payments, but this money came from cash deposited by other investors.

Mr Greig claimed the fraud was carried out by a former business partner, but a jury found him guilty after a four-week trial at the High Court in Edinburgh.

Jennifer Harrower, procurator fiscal for specialist casework, said: “The scale of Alistair Greig’s fraud was vast – he spent years lying to many people in order to defraud them out of millions of pounds.

“In some cases, he took the life savings of people who had worked to save for retirement. All this to fund his own lifestyle.

“This sentence is the end of a lengthy and complex investigation that required the dedication of a skilled and knowledgeable team to bring it to prosecution.”