However, Knight, 60, who was on the run in Spain for 10 years, denied that he had taken part in the theft in 1983, which was then the largest cash robbery in British history.
Sentencing him, Judge Gerald Gordon said: "Clearly, I do not know what precise role you played. But professional robbers such as those involved are not going to hand over the sort of sums you got unless the person to whom they give it is very deeply involved himself." Knight, the former husband of the actress Barbara Windsor, stood with his hands clasped in front of him as he listened to the judge and showed no flicker of emotion as sentence was passed.
He was the sixth person to be jailed in connection with the robbery at Shoreditch, east London, on Easter Monday 12 years ago, in which a security guard was drenched with petrol and threatened that he would be set alight unless he handed over the keys tothe vault.
After the hearing, Det Supt Iain Malone of Scotland Yard's Flying Squad said the sentence reflected those handed down to other members of the gang. He said his team would continue to pursue the four still at large, against whom arrest warrants had been issued.
He admitted some surprise that Knight had flown back from the Costa del Sol last year, but said the police had not done any deal with Knight over the charges and that he had always known he faced a long prison term.
Knight denied taking part in the robbery, and Michael Worsley QC, for the prosecution, agreed that the charge should lie on the file. But he pleaded guilty to handling £314,813 in used banknotes.
Much of the money was deposited with Miss Windsor's accountants, Fox Associates, in large sums of cash in the weeks immediately after the robbery, as a "cover plan" to avoid using a bank where questions might have been asked, Mr Worsley said.
He said Miss Windsor knew nothing of the source of the money, even though some had been used to repay debts to her, and pointed out that she had been away working in the theatre when the bulk of the cash was deposited.
Knight's mistress, Sue Haylock, 42, later to become his third wife, also deposited sums of cash in her bank account. Several months after the robbery, she bought a new Mercedes-Benz with bundles of bank notes in "thousand-pound wads", Mr Worsley said.
The bulk of the money, though, was transferred from Knight's accountants to bank accounts in Spain and eventually spent on several flats, an Indian restaurant and a nightclub. Following the arrest of his brother in January 1984, Knight fled to Spain, to be followed the next day by Miss Haylock, who initially returned to England to transfer more of the "ill-gotten gains" out of the country.
But by the time of his return to Luton airport last May, Knight, as far as police could establish, was penniless with even his property assets bought with the stolen cash gone. Judge Gordon said he therefore would not be able to make a compensation orderin favour of Security Express. He told Knight: "You benefited by an enormous amount and not one penny has been recovered."