Former fugitive tycoon Asil Nadir has been found guilty of 10 counts of stealing £28.6 million.
The amount stolen by the multimillionaire, who fled Britain in 1993 but returned in 2010, is the equivalent of £61,829,627 today, the Old Bailey was told.
Nadir, of Mayfair, London, plundered the millions from his Polly Peck International business empire between 1987 and 1990.
Asil Nadir has been found guilty of nine counts of theft
He denied 13 counts of theft of £34 million. Nadir, who was cleared of three counts, will be sentenced on Thursday.
Nadir, 71, spent 17 years on the run in Northern Cyprus after Polly Peck International (PPI) collapsed.
He returned convinced he could clear his name, but after a seven-month trial at the Old Bailey, jurors convicted him.
Polly Peck was a success story of the Thatcher era and was a top-performing company on the Stock Exchange.
It crashed in 1990 with debts of £550 million. Creditors got a fraction of what they were owed and shareholders received nothing.
Nadir was arrested but was secretly flown out of Britain in May 1993 before he could face trial.
Nadir, once 36th on the Sunday Times Rich List, was originally accused of 66 counts, alleging theft of £380 million.
He plundered the conglomerate, spiriting away the money into a "black hole" through a complex series of transactions.
These included transferring cash to a bank he owned in the Turkish Republic of Northern Cyprus.
The money went on jewels, furniture, luxury properties and making his friends and family rich, jurors were told.
Nadir had been a favourite of prime minister Margaret Thatcher and PPI, once a lowly clothing company in the East End of London, was a modern-day success story.
At one point, it was the Stock Exchange's fastest-growing company, with 200 international subsidiaries dealing in electronics, food, textiles and leisure.
The tycoon was arrested and was due to go on trial in 1993, but was secretly flown out of Britain in a private plane.
He lived the life of a free man in Cyprus, where he was born, but was restricted to exile on the Turkish northern sector of the Mediterranean island.
A second marriage to Nur, a graduate 43 years younger than him, did not quell his desire to return to England.
He flew back in August 2010 after a judge allowed him bail for the two years of court proceedings which followed.
Nadir denied the 13 charges, maintaining his elderly mother Safiye had offset the transfers to Cypriot subsidiaries with Turkish lira.
Philip Shears QC, prosecuting, said this was laughable as it would have taken a mountain of cash 300 times higher than Nelson's Column to match the sterling.
Nadir abused his position as chairman and chief executive of PPI to steal from the company, said Mr Shears.
He said: "Asil Nadir was the dominant force in PPI. He maintained a direct control over its operations, directing its affairs in an autocratic manner, and refusing to tolerate rival sources of power - or constraints upon his freedom of action.
"He abused that power and helped himself to tens of millions of pounds of PPI's money.
"He caused the transfer from the three PPI accounts which he dishonestly routed away to benefit himself, his family or associates."
In December 1989, accounts showed £202.6 million - 81% of PPI's cash balances - in the subsidiaries in Turkey and Northern Cyprus.
Most of the funds ended up "within a fairly complex structure of offshore companies" based in Switzerland, the Bahamas and elsewhere, said Mr Shears.
Some £26.2 million was used to secretly buy shares in PPI by companies owned by Nadir to bolster its share value.
Stolen money was also paid into Nadir family trusts and companies - and to pay off his debts.
His mother's bank account in northern Cyprus was used to receive stolen money, the court heard.
Attempts to get cash back to the UK when the company got into trouble were fruitless except for a "very small fraction".
Mr Shears said: "When the administrators went to northern Cyprus, they effectively found no cash at all, just a black hole.
"There is a perfectly good explanation for that - it had gone. Asil Nadir had stolen it."
PPI's headquarters was in Berkeley Square, central London, and it had trading centres from Hong Kong to New York.
Nadir insisted that millions of pounds could be moved around with only his signature as authorisation.
In September 1990, after Nadir's South Audley Management company was raided by the Serious Fraud Office, his chauffeur removed documents from Switzerland to northern Cyprus, said Mr Shears.
The delay in bringing Nadir to trial meant some witness statements had to be read, as 18 potential witnesses had died.
Another unforeseen consequence was that microscopic bugs were released when the files in 1,400 storage boxes were reopened.
One member of staff was treated in hospital and other staff were ordered to wear protective clothing, and the boxes were given thermal treatment.
Nadir told the court his actions were for the good of the company but it was placed into administration in his absence.
He said he fled because he was "a broken man without hope" but had to return, despite doctor's orders, because he could not live "with injustice".
The trial began in January after a series of preparatory hearings, and should have lasted four months.
But illness among jurors resulted in two being discharged and the trial lasting seven months and costing around an estimated £10 million.
Nadir was granted legal aid for his defence costs and he will be expected to pay some of it back.
Pilot Peter Dimond and accountant Elizabeth Forsyth were jailed after Nadir fled but were later released on appeal.
Nur Nadir said her husband was planning to appeal against the verdicts.
She said: "A guilty man does not come back to face justice of his own accord.
"My husband came back voluntarily. Polly Peck was his life.
"He wants justice for himself and for the tens of thousands of shareholders and employees.
"This unhappy affair is certainly not over yet."
Mrs Nadir, 28, has been by her husband's side throughout the trial and exchanged affectionate looks as he stood in the dock.
Nadir's wife Nur, 28, made no comment to reporters as she left court and entered a car waiting outside the building.
"We welcome the verdicts and are pleased that justice has at least been done in this long running case," Claire Whitaker of the Serious Fraud Office said in a statement outside court.