A world-renowned US economist who was part of a secret “Plan B” team devised by Greece’s former finance minister, has denied being involved in a “criminal gang” intent on bringing the drachma back to the country. James K. Galbraith, a professor of government at the University of Texas and long-time friend of Yanis Varoufakis, coordinated a five-man effort which advised Athens on the emergency measures it could take should creditors force Greece out of the eurozone. The clandestine plans were made public last week following the airing of a private coversation between Mr Varoufakis and international investors in London. Greece’s supreme court has since lodged two private lawsuits against the former minister with the Greek parliament. They are said to be related to charges of treason and the formation of a “criminal gang”. But speaking to The Telegraph, Mr Galbraith said he has received no official communication from Greek authorities about his own involvement and does not expect an extradition order to face trial in the country. “If questions come my way I'll be happy to answer them” said Mr Galbraith. “We will see what happens, but I would be surprised if there is anything more than a fact finding mission [from Greek authorities] at this stage.” "We were not involved in any policy discussions and we had no role in the negotiating strategy" James Galbraith The US economist spent five months in Greece until July and was not paid for his efforts. The identity of the other three members has not been revealed, but Mr Varoufakis currently enjoys parliamentary immunity from criminal prosecution. “We were content to stay completely out of view” said Mr Galbraith, who described his work a “precautionary troubleshooting” for the government after it had been threatened with a collapse of its banking system from Europe’s creditors. “It was a situation where any leaks would have done harm, and so we proceeded carefully with that very much in mind. No leaks occurred, we were not involved in any policy discussions and we had no role in the negotiating strategy.” Mr Galbraith also distanced himself from a separate finance ministry operation to devise a system of “parallel liquidity” that would allow the government to continue paying its suppliers in the face of the cash squeeze. Mr Varoufakis has courted controversy after telling investors he asked a childhood friend and professor at Columbia University to “hack” into the computer system of the equivalent of Greece’s inland revenue body, to set up the payments network. The revelation that he sought access to private taxpayer information has let to opposition parties in Greece calling for a full inquiry into the operation. Mr Varoufakis also said the system, which was denominated in euros, could be switched to drachmas at the "flick of a button". But Mr Galbraith, who has never met the Columbia professor, downplayed the implications of the plan as an “administrative” matter for the finance ministry. “It could have been implemented within the eurozone, and had no implications for the exit strategy”, he said. “It would have facilitated payments between the state and its counterparties and possibly could have been extended to private sector liquidity”. Prime Minister Alexis Tsipras rallied behind his beleaguered former minister on Friday, confirming that he tasked him with the responsibility to “defend” the country after creditors had also made contingency plans for a Greek exit. Mr Galbraith described attempts to paint Mr Varoufakis as a rogue finance minister in some parts of Greek media and political opposition as “defeated, discredited and desperate”. The son of the pre-eminent economist of the Great Depression, John Kenneth Galbraith, he said the working group looked at “scrip” currency issuance in the state of Detroit in the 1930s, and California’s IOUs in the 2000s. California last issued temporary coupons to pay bills to contractors when liquidity seized up after the Lehman crisis in 2008. “I've never seen anyone work so hard or so selflessly on behalf of his country” James Galbraith on Yanis Varoufakis Two days before his resignation, Mr Varoufakis told The Telegraph the government should have chosen the California option a week before a decision to hold a referendum on bail-out terms on July 5. The revelation has been touted as bringing about the eventual downfall of the self-styled “erratic Marxist”. But Mr Galbraith defended his friend as a man who had remained committed to keeping Greece inside the single currency throughout six months of ill-tempered negotiations. “I've never seen anyone work so hard or so selflessly on behalf of his country” he said. Prime Minister Tsipras now faces another month of drawn out negotiations with the Troika who have returned to Greece for the first time in a year. The premier has managed to hold off a rebellion within his Syriza party after memebers postponed an internal ballot on bail-out conditions until September. Mr Galbraith said he expected the former finance minister to stay loyal to the government despite previously denouncing the terms attached to a third rescue package as the equivalent of Greece’s “Treaty of Versailles”. “Yanis has no personal political ambitions”, said the professor. “The internal politics of the party remain solid. There are many relationships there which go back a long way, and they all have a good reasons to trust each other. The most likely thing right now is that the coalition sticks together.” Join the conversation about this story » NOW WATCH: People doing backflips on a two-inch wide strap is a real sport called slacklining