More stories coming out of the guilty plea by former UBS American banker Bradley Birknefeld:

UBS earned about $US200 million a year in revenue by helping high-income clients through such practices as setting up sham entities in tax havens including Switzerland, Panama, British Virgin Islands, Hong Kong and Liechtenstein, Birkenfeld said.

In one case, Birkenfeld even agreed to buy diamonds for a US client using Swiss funds and ''smuggled the diamonds into the United States in a toothpaste tube,'' Birkenfeld said.

UBS spokesman Mark Arena declined to comment

I have known about, and talked about the sham entities for some time, but not in my wildest imagination did I presume UBS would be smuggling diamonds. Of course it is possible that Birkenfeld is exaggerating. Somehow though I doubt it. It is much more likely that offshore operators, even those with the status of UBS, are more sordid than I would ever want to imagine.

This model is corrupt and corrupting. There is no defence for it. Tax havens have to be closed.