Four people have been jailed for a total of 21 years for their part in a counterfeit money scam described as "sophisticated and audacious".
BBC reporters secretly filmed the gang at work
The gang printed more than £2.5m worth of fake £10 notes and $3.5m worth of counterfeit US notes.
They were caught after police raided a printing firm in Ashton-under-Lyne, Greater Manchester, in December 2002.
Det Supt Nick Lewis said: "The potential to undermine the economy of the UK and US was very significant."
The scam was uncovered after a joint operation between the National Crime Squad and the US Secret Service, Manchester's Minshull Street Crown Court heard.
When police raided the bogus business premises on the Cavendish Industrial Estate on Dean Street they found counterfeiting machinery, including a four-colour printer, a guillotine, papers and inks.
Det Supt Lewis, from the National Crime Squad, said: "This is one of the most sophisticated counterfeit printing operations we've uncovered in recent years.
"These were good quality banknotes, good quality travellers' cheques which could have had a very significant undermining effect on those economies."
An undercover BBC investigations team had also secretly filmed the gang producing £10 and £20 notes and $100 bills.
One of the reporters, James Raven, 44, of Bolton, was jailed for life in August 2004 after being convicted of murder in an unconnected case.
Ringleader Anatasios Arnaouti was the 'prime mover'
Judge Bernard Lever said the BBC "must ensure they are extremely careful in vetting undercover operatives and must understand the frustrations of police involved in the other matter".
He added: "However, senior managers and employed journalists at the BBC acted in good faith and two people sentenced today were sentenced on evidence from the BBC."
The BBC said in a statement: "We are pleased that a major piece of BBC investigative journalism has led to the exposure of serious crime and the bringing to justice of serious criminals.
"However, we will be studying the judge's remarks very carefully. We have already updated our guidelines and we will assess what lessons can be learned for the future."
Ringleader Anatasios Arnaouti, 37, of Atherton Close, Failsworth, Manchester, was jailed for eight years for conspiracy to make counterfeit currency, conspiracy to pass counterfeit currency and conspiracy to handle stolen goods.
The judge told him he was a highly intelligent and devious criminal, adding: "You were the instigator and prime mover and this massive enterprise was your brainchild."
Those sentenced were:
- Anatasios Arnaouti, 37, of Atherton Close, Failsworth, Manchester, was jailed for eight years for conspiracy to make counterfeit currency, conspiracy to pass counterfeit currency and conspiracy to handle stolen goods.
- David Harper, 37, of Denman Drive, Tuebrook, Liverpool, was convicted of conspiracy to make counterfeit currency and American Express holograms and jailed for six-and-a-half years.
- Philip Raynor, 48, of Rathbone Street, Rochdale, Greater Manchester, was jailed for four years after pleading guilty to conspiracy to make counterfeit currency, conspiracy to pass counterfeit currency and conspiracy to handle stolen goods.
- Robert 'Dwayne' Whittaker, 42, of Longfellow Street, Toxteth, Liverpool, was jailed for two-and-a-half years after admitting conspiracy to tender counterfeit currency.
- Alison Jane Wyatt, 34, of St Christopher's Drive, Romiley, Greater Manchester, was given community service after admitting passing counterfeit currency and possession of counterfeit currency with intent to supply.
In April of this year, Ishwar Ashok Daryanani, 44, of Camp Road, Woolton, Liverpool, received a 12 month jail sentence, suspended for two years, and was fined £10,000 after admitting possession of counterfeit $100 and £20 notes and possession of cannabis.
Two other defendants have yet to be sentenced.