Elveden is the Metropolitan Police's inquiry into allegations of the illegal passing on of information by public officials to journalists.

BBC: New Scotland Yard sign

In recent years criticism of banking secrecy has centred on the risk of money laundering, the practice of disguising funds from illegal sources by passing them through secret accounts until their origins can no longer be traced.

ECONOMIST: Filthy lucre is out, clean lucre is in

ENVIRONMENTALISTS, scouring Cambodia's jungles for evidence of illegal logging, ask a passing farmer where trees are being cut down.

ECONOMIST: Just chopping it down

What will be the level of illegal immigration within 3 years after passing a bill to make using E-Verify mandatory?

FORBES: Should Americans Get Permission from the Federal Government Before Being Allowed to Start a New Job? That's One of the Questions for Congressional Supporters of the New E-Verify Bill

Illegal immigrants could be held in the centre after passing through British immigration controls in France - then sent back to their home countries on charter flights.

BBC: Immigrant amnesty 'road to hell'

Hiking to the summit, which requires passing through land that is privately owned, has been illegal since 2009.

BBC: Lakeside treks in a geothermal land

It's technically illegal, but easy enough, to flag down pretty much any passing car and pay for a ride around the city, although there's no guarantee of the car, or the driver, being roadworthy.

CNN: An insider's guide to Havana

People passing through the court system, therefore, seem to account for most illegal drug demand.

ECONOMIST: Drugs