Stronger scrutiny is required of elected police commissioners to prevent "maverick decision making", a damning report by MPs has warned.
Police and Crime Commissioners (PCCs) are required by law to reveal certain financial data but a survey by the Home Affairs Select Committee found that only a quarter of the officials had done so.
The committee has called for a national register of PCCs' interests, pay, perks and hospitality, despite the idea being previously shot down by the Home Secretary Theresa May.
The report follows a string of heavily-criticised decisions made by commissioners including the suspension of a chief constable in Lincolnshire and the hiring of a youth commissioner in Kent.
"A national register is vital for local accountability," Keith Vaz MP, committee chairman, said. "We need to guard against maverick decision-making."
PCCs, which replaced existing police authorities in 41 force areas across England and Wales, were handed the power to set force budgets and even hire and fire chief constables. Just 15.1% of registered voters took part in the November 2012 PCC election - the lowest recorded level of participation at a peacetime non-local government election in Britain. In areas such as Greater Manchester, commissioners represent the interests of millions of people.
The committee's report accused the Home Secretary of being been "keen to distance herself from any responsibility to assess the performance of the PCCs" after she told the Committee they were ultimately "accountable to the electorate''. Her comments came after the Government said the College of Policing was to publish a register of interests for chief constables.
Mr Vaz said: "The Government is going to publish a register of chief constables' interests, but has so far refused to do so for PCCs, who share the power over policing."
The committee found that only 10 out of the 41 PCCs had met statutory obligations and published full financial data required of them, which includes expenses and contracts tendered. And five commissioners as at the beginning of May had still not published annual budget data online, the report said. These were Matthew Grove for Humberside, Sir Clive Loader for Leicestershire, Stephen Bett for Norfolk, Winston Roddick for North Wales and Tim Passmore for Suffolk.
The report said the committee did not accept that a national register is unnecessary and there was "unanimous agreement" among the PCCs called for evidence that it would be a "fair and helpful" way to hold them to account. It suggested that a national body such as Her Majesty's Inspectorate of Constabulary (HMIC) could be responsible for compiling and publishing the register.