The Williams case - the worst financial scandal ever to hit the Met - prompted critical reports by the National Audit Office and the Commons Public Accounts Committee, which castigated the Yard for lax scrutiny.
A new head of internal audit for the Met will join the force this week. He is Peter Tickner, a fellow of the Institute of Internal Auditors and currently the head of internal audit at the Treasury.
Mr Tickner is higher up the civil service ladder than previous holders of the Yard post. His sideways move reflects Government embarrassment at the ease with which Mr Williams was able to take pounds 5m of police funds without anyone noticing.
The number of auditors at the Yard is to rise from seven to 20. Mr Howard is insisting that, in future, his officials hold quarterly meetings with Mr Tickner to go through the Yard's books.
Despite questions having been raised about his trustworthiness when he was involved in managing the police's civilian staff welfare fund, Mr Williams was put in sole charge of one the Yard's most secret projects, to operate a specially adapted aircraft to spy on suspected IRA terrorists.
The desire of his superiors to keep the aircraft's existence under wraps allowed Mr Williams a free hand. When he needed cash for the plane's running expenses, all he had to do was ask. The absence of scrutiny proved too good an opportunity to miss, and the quiet, career civil servant from suburban New Malden in Surrey committed theft on a grand scale with total ease. Even when he lavished millions on the Scottish Highlands village of Tomintoul, turning himself into the self-styled local laird in the process, nobody at the Met rumbled him. It was only a tip-off from a bank, suspicious at Williams' high-lifestyle on a grade six civil servant's salary, that sparked his downfall.
MPs on the Public Accounts Committee were scathing in their condemnation. Police chiefs admitted mistakes had been made and promised they would not happen again.
Mr Howard has demanded that in future, no matter how secret the operation, financial checks will still be applied.