Foreign companies that own property in the UK will be forced to make public who really owns them, David Cameron announced as he admitted corruption affects Britain.
The Prime Minister warned that corruption is the "cancer at the heart of so many of our problems" as international leaders gathered in London for a summit to tackle the problem.
Tax-dodging destroys jobs, holds back growth, traps people in poverty and can undermine security by making citizens more susceptible to the "poisonous ideology of extremists", he said.
Mr Cameron said there had long been an "international taboo" over stirring up concerns.
"I profoundly believe that this has to change - and it has to change in every country. Make no mistake, corruption affects us all, Britain included," he said.
Overseas firms will have to sign up to a new public register if they own or buy property or if they want to bid for central government contracts.
Foreign companies own around 100,000 properties across England and Wales, with more than 44,000 in London alone.
The move is aimed at stopping money being laundered or hidden using London's property market.
Mr Cameron said: "Corruption is the cancer at the heart of so many of our problems in the world today. It destroys jobs and holds back growth, costing the world economy billions of pounds every year.
"It traps the poorest in the most desperate poverty as corrupt governments around the world syphon off funds and prevent hard-working people from getting the revenues and benefits of growth that are rightfully theirs."
Mr Cameron is facing calls to tackle tax secrecy in Britain's overseas territories and Crown dependencies at the summit.
Former prime minister Gordon Brown urged the premier to join other EU states in imposing sanctions against islands that continue to act as tax havens for the wealthy.
Amid a backlash over the Panama Papers, Mr Cameron last month announced that the overseas territories and Crown dependencies - such as the British Virgin Islands and Jersey - had agreed to provide UK tax and law enforcement agencies with full access to company ownership details.
Downing Street said 40 jurisdictions, including some of the islands, with major financial centres have now agreed to share their beneficial ownership registers with other countries.
Mr Cameron's position as host of the two-day summit was made more awkward after he was caught on camera branding two participating states - Nigeria and Afghanistan - as "fantastically corrupt".
The two countries, along with France and the Netherlands, will commit at the summit to launching their own public registers of true company ownership, No 10 said.
Britain is creating an international anti-corruption co-ordination centre in London with backing from the United States, Canada, Australia, New Zealand, Switzerland and Interpol, which will work across borders to investigate corrupt elites and recover stolen assets.
US secretary of state John Kerry, who is attending the summit, said corruption was "exploding" and the world was not doing enough to stamp out the problem.
Mr Cameron said: "The evil of corruption reaches into every corner of the world. It lies at the heart of the most urgent problems we face - from economic uncertainty, to endemic poverty, to the ever-present threat of radicalisation and extremism.
"A global problem needs a truly global solution. It needs an unprecedented, courageous commitment from world leaders to stand united, to speak into the silence and to demand change.
"That is why I am hosting this summit. Today is just the start of a more co-ordinated, ambitious global effort to defeat corruption."