Twelve million aliens in the US

The number of illegal immigrants living and working in the United States has reached a high of 11.5 million to 12 million people - more than half Australia's population.

The new estimates, part of a study by the Pew Hispanic Centre in Washington, show an increase in illegal immigration of from 400,000 to nearly one million people during the past year, as more overstay their visas and cross the border illegally in search of jobs.