The entire campaign team resigned yesterday within hours of being contacted by The Sunday Telegraph.
Lincolnshire may have been chosen because the county's police are already "outsourcing" pioneers.
The troubled firm G4S has recently taken over key functions at the force, including its custody suites, central control room and firearms licensing department. G4S also plans a new central police station in a village outside Lincoln, with the existing city centre station closed and sold for housing.
After G4S's security failures at the Olympics, Mr Barrett strongly backed the company, saying that the Lincolnshire deal was "working well." He attacked his rival candidates, who suggested cancelling the deal, for making "bankrupt promises" and "playing politics".
Investigation of Mr Barrett's campaign website reveals that it is registered to a New York and Washington-based "political action committee", MatthewPAC, part of The Fund for the New American Century, whose website says it is "dedicated to building America's future by supporting candidates who share our vision for reform and innovation".
The fund is expanding in Europe and is advertising for a UK-based "assistant to the executive chairman" on a salary of up to £55,000.
Mr Barrett's campaign has also advertised for staff, speaking of the "sophisticated and wide-ranging support available from our US and UK-based consultants".
The Sunday Telegraph has established that Matthew de Unger Brown, Mr Barrett's "special adviser", campaign manager and press spokesman until yesterday, is also chairman of the Fund for the New American Century.
"We support Republican candidates. It is a centre-Right organisation," Mr de Unger Brown said. "I don't think that neo-con would be an unfair description."
One of Mr Barrett's opponents in the election, David Bowles, another independent and former chief executive of Lincolnshire county council, said: "It is a very slick campaign but it appears that Mervyn is no more than a puppet.
"Every time I have tried to contact him, the response has always come back from Matthew and every time I've tried to meet him it's been Matthew I've met instead."
Mr Bowles claimed that last week Mr de Unger Brown asked to meet him to discuss the possibility of an electoral deal, with Mr Barrett becoming his deputy.
"Matthew told me that the funding for Mervyn's campaign was coming from people with an interest in police sector privatisation," Mr Bowles said.
"I was told that any deal including Mervyn would be conditional on that funding continuing, and I made it clear that I was not prepared to accept a penny."
Mr de Unger Brown said that his organisation was also backing other Police and Crime Commissioner (PCC) candidates elsewhere in England, Mr Bowles added.
Directly elected PCCs, one for each force area outside London, were part of one of the Government's flagship policing reforms, intended to "sweep away" police bureaucracy and "give people real control" over their force.
The commissioners, paid up to £100,000 a year, will replace unelected police authorities and control police budgets and strategy, though "operational matters" will remain in the hands of the local chief constable.
Some analysts have long feared that a low turnout in the November 15 elections could hand "Trojan horse" candidates power and control over policing with only a few thousand votes. The Electoral Reform Society warned last month that the poll could become a farce, with turnout of just 18.5 per cent.
Mr de Unger Brown said last night: "The Fund for the New American Century takes, both in the UK and the US, funding from a variety of corporate donors.
"Mervyn Barrett for PCC has not taken - directly - any money from organisations that have any interest in commissioning outsourced services." He refused to deny that money had been supplied via the fund.
Mr de Unger Brown said his campaign would comply with all disclosure requirements of electoral law, but under a loophole in Electoral Commission rules, independent candidates do not have to publish details of their donors until after the election. He declined to say which companies were providing funding, but said the campaign envisaged spending almost £100,000 by polling day.
A few hours after being contacted by The Sunday Telegraph, Mr de Unger Brown and his campaign team resigned.
Shortly after announcing his candidacy, Companies House records show, Mr Barrett established a new company, Trinity Advisory Ltd, based at his home.
It is not clear what the purpose of the company is or what advice Mr Barrett is offering and no accounts have yet been filed.
G4S said that it had not funded any PCC campaign.
Critics of the PCC elections have raised fears over the democratic accountability of candidates elected on very small turnouts.
"The focus on turnout could make us miss a real opportunity to debate the liberal consensus on how to tackle crime," said Sam Chapman, a former police officer and unsuccessful candidate for the Conservative PCC nomination in Lancashire.
"There are police and other interests who don't want PCCs and want to make this election unsuccessful. Some of the Government's decisions have played into their hands."
During the passage of the legislation, the Association of Chief Police Officers (Acpo), which represents chief constables, pushed hard for drastic restrictions on candidates. Any conviction for a criminal offence carrying a potential prison sentence is a bar to standing, even if the person was not themselves imprisoned and even if they were a juvenile at the time.
One of the best-known figures to consider standing, the Falklands war hero Simon Weston, fell foul of the rule.
In the mid-1970s, as a 14-year-old, Mr Weston, who is now 51, was fined £30 and put on probation for riding in a stolen car, though he did not know it was stolen. Another well-qualified candidate, Bob Ashford, a
former senior executive in the youth justice system, was forced out because of a minor conviction in 1966, when he was 13.
Other rules include a strict residential qualification which bars many potential candidates, such as the broadcaster Nick Ross, who do not live in the county where they want to stand.
The depth of the candidate problem is shown by the fact that virtually the only prominent figure left in the race is Lord Prescott, who is standing in Humberside, one of 41 police forces in England and Wales to be holding elections. "Some of the candidates are quite good," said Mr Chapman. "But some are mediocre placemen, councillors and police authority members who are being very conventional."
So what? many voters may say: policing should be left to the police. But with the scandal of Hillsborough fresh in the mind - and five chief constables, in the last six months alone, sacked, suspended, forced to resign or placed under investigation - it appears hard to believe that police leadership cannot be improved.
"The police have essentially been unreformed for a long time and chief constables are used to doing what they want," said Mr Chapman.
"The pity of these elections is that there could have been a real debate about crime and policing, but we haven't got it yet."
