Gang members have been jailed for carrying out a "clever, persistent and pitiless" multi-million-pound bank fraud and money laundering scam.
A pipeline of tiered bank accounts made up part of a "series of complicated arrangements" used to drain money from small businesses, which was never recovered, a court heard.
The accounts were targeted in a "vishing" scam masterminded by Feezan Hameed, 23, from Glasgow, London's Southwark Crown Court was told.
He made phone calls posing as an official from a bank's fraud department and persuaded victims to reveal financial information or use card readers to authorise payments online.
Several members of the gang, which netted £19 million between August 2013 and October 2015, were sentenced on Wednesday.
Judge Peter Testar described Hameed as "persuasive, authoritative to the point of being bullying" and "controlling" as he persuaded victims.
He was sentenced to 11 years in prison.
The judge said: "Anyone who had heard the calls would have been struck and affected by them. There was a great deal of sophistication in the fraud.
"The people behind the fraud would have need to have an understanding of bank systems. The people involved seem to be able to take control of telephone lines of business so as to shut them out of the banks."
A previous hearing heard that Hameed fled to Paris as the rest of the gang were arrested, but was extradited back to Britain for trial.
The judge said "no-one really knows" where all the money ended up, but £100,000 seems to have been spent in Harrods.
Hameed and colleagues from Glasgow enjoyed the use of Rolls-Royce cars and went to nightclubs on the proceeds.
In one case, around £750,000 was taken from an account within seconds of the conman's cold call, and a firm of solicitors who were also targeted found their account had been emptied of more than £2 million, the court was told.
The bogus calls would have seemed credible to the workers who answered because Hameed's gang had "corrupted" some bank employees to help with the scam. Information such as latest transactions and the name of the account's relationship manager gave credibility to the call.
The gang knew withdrawals of more than £100,000 would trigger a bank's fraud security alert, and prosecutor Michael Shorrock QC said: "There were a number of transfers of just under £100,000."
Of the £19 million that was taken, £11 million was taken in the last few months, right up to two days before the fraudsters were arrested.
A network of accounts, using foreign students who had left the country, was set up to ensure the money was swiftly siphoned away.
The gang also created fictitious accounts.
Nouman Chaudhary, 21, of Glasgow, was sentenced to three and a half years for conspiracy to money launder.
Judge Testar said Chaudhary "frittered money away on ephemeral junk" at Harrods and was present when £48,000 was spent at the luxury department store, and also "threw himself fully into the lavish lifestyle" including expensive hotels, cars and nightclubs.
He travelled first class to Dubai and Pakistan. Abdul Iqbal, 23, of Edinburgh, was sentenced to 21 months for conspiracy to money launder.
Hameed treated him as a butler or servant but he got a £3,500 watch from the scheme and was present at Harrods when £70,000 was spent.
He accepted that £110,000 went through his account but he "threw himself happily into the task and enjoyed the life that Feezan Hameed brought him", the judge said.
Syed Ali Amish, 24, of Luton, was sentenced to 32 months for conspiracy to launder money.
The judge said he played a "significant role" in the gang including recruiting others to provide bank accounts and trying to arrange accounts himself.
Mohammed Mehtab, 35, of Watford, was given an eight-month suspended prison sentence after pleading guilty to conspiracy to launder money.
He allowed more than £9,000 to go through his account. Syed Haider, 31, of Slough, was sentenced to five years in prison for conspiracy to defraud and conspiracy to transfer criminal property.
Judge Testar said he regarded Haider as having had a "leading role in the money laundering".
His wife, Bushra Haider, 30, also from Slough, was given a two-year suspended sentence after pleading guilty to one count of conspiracy to launder money.
Judge Testar said her case had "troubled" him a "great deal" because she was pregnant when arrested.
Her child was born two days after she was released on bail, the judge said.
Bilal Ahmed, 26, of Ilford, Essex, played a "significant role" in the scheme.
He pleaded guilty to conspiracy to launder money and was sentenced to three years and four months in prison.
"While he was playing a comparatively small part in the scheme of things, he was nevertheless playing his part in the greater whole," the judge said.
In his closing remarks, Judge Testar praised the work of police officers from West Yorkshire, Greater Manchester and the Metropolitan Police who were involved in the case.
He said: "The work which these officers did was heroic and had heroic proportions. I'm very happy to commend the officers who played the principle roles in this inquiry.
"It's not only commendable that they did the work that they did, but that the cooperation between these different forces took place to the extent that they did."