WHEN it comes to corruption, Venezuela has long languished near the bottom of the international league table. According to the latest index of perceptions of corruption compiled each year by Transparency International, a Berlin-based watchdog, only eight out of the list of 176 countries were seen as more graft-ridden. Even places like Haiti and Zimbabwe ranked higher. The organisation’s Venezuela chapter found that 65% of respondents in a recent survey thought corruption had worsened in the previous two years. Well over half thought government measures to tackle it were ineffective.

Enter Nicolás Maduro, elected as president in April after Hugo Chávez died of cancer before he could be sworn in for a third six-year term. Mr Maduro, a former bus driver who was Chávez’s foreign minister, has said that fighting corruption is a priority for his government. Several mid-level officials have been arrested.

One of the biggest cases concerns Ferrominera, a state-owned iron-ore miner and processor in the south-eastern state of Bolívar. After years of protests by its workers, some of whom were prosecuted for their pains, Ferrominera’s chairman, Radwan Sabbagh, was arrested in June and accused by Mr Maduro of “bleeding the company dry”. More arrests followed, including that of Yamal Mustafá, a businessman with close ties to Bolivar’s state governor, Francisco Rangel Gómez.

Documents from a military-intelligence investigation, leaked to federal legislators and a local newspaper, revealed scams worth an astonishing $1.2 billion, including sales of ore to intermediaries at a fraction of its real value in exchange for huge kickbacks. It may be even worse. Ricardo Menéndez, the industry minister, recently admitted that there was “much more corruption in Ferrominera than has been made public”. The army colonel sent to investigate the case in 2011 is alleged to have made tens of millions of dollars blackmailing Ferrominera’s managers and Mr Mustafá. He, too, is now awaiting trial.

Even the Ferrominera case pales beside the mountains of cash that may have been swindled from the government’s foreign-exchange regulator, Cadivi. With the black-market rate for the dollar currently more than five times the official rate of 6.3 bolívars, the amount of money that can be made from fraudulent import schemes is colossal. Last year Cadivi handed over $59 billion in all. But Jorge Giordani, the planning minister, and Edmée Betancourt, the Central Bank governor, say up to a third of that could have been funnelled to fake companies. Ms Betancourt put “artificial demand” at $15 billion-20 billion.

Claims of corruption involve some of the most senior figures in Mr Chávez’s “Bolivarian revolution” (named for Simón Bolívar, Venezuela’s independence hero). In an audio tape leaked in May, Mario Silva, a presenter on state television and (it now appears) a Cuban agent, enumerated to his handler the sources of illicit finance he said were available to Diosdado Cabello, speaker of parliament and leader of the ruling socialist party, who is a potential rival to Mr Maduro. They included the tax authority, headed by Mr Cabello’s brother, and Cadivi. Mr Cabello dismissed the audio tape as a fake, the public prosecutor has yet to investigate and Mr Silva lost his job.

Instead, Mr Cabello has gone after the opposition. Claiming that Richard Mardo, an opposition legislator, was guilty of tax evasion and money laundering, he arranged for him to be stripped of his parliamentary immunity. When the opposition protested against political persecution, President Maduro organised a countermarch. He used the government’s power to force all television channels to carry his speeches to brand the opposition as corrupt—without any sense of irony.

Mr Mardo’s case involves a paltry $400,000 or so in what he says were campaign contributions from business. No public money was embezzled: in fact the legislator did not hold public office at the time. Nor has evidence been presented that he evaded tax or that the funds were of illicit origin, despite attempts by the government to compare Mr Mardo to Pablo Escobar, a late drug baron. On the other hand, Mr Cabello has refused to allow any parliamentary debate on several recent multi-million-dollar corruption scandals. One involved managers of PDVAL, a state company which allowed hundreds of thousands of tonnes of food to rot in shipping containers. Three were arrested, but they were later quietly released and given other jobs.

It has been left to the American courts to air several claims of corruption involving Venezuelans. Otto Reich, a former State-Department official, last month sued Derwick Associates, a firm whose partners are Venezuelans. Mr Reich alleges defamation; he also claims that the company paid large bribes to Venezuelan officials to obtain contracts to build power stations. Derwick and its partners deny the allegations. Details of the contracts appeared in the Venezuelan press months ago, but failed to spark an investigation. “There are no untouchables,” declares President Maduro. So far few have been touched.