It's difficult to remember the last time National Irish Bank had good news to report. Its last set of results was so downbeat the bank did not even bother to notify the media, as is the normal course with all public institutions. And it still faces a tax bill on bogus non-resident accounts once the Revenue ends its inquiry into all Irish deposit-holders.

Now the bank is under fire from customers who invested in illegal offshore instruments. A number are suing the bank, claiming they bought offshore bonds in good faith and were not aware of possible tax problems. Further claims are expected.

Around 280 customers were involved for sums of around £50 million - an average of nearly £180,000 per customer.

Even stripping out those resident in Ireland - who could not legitimately invest in such products - the figure is staggering.

Some 100 customers invested £14 million - an average of £140,000 per customer.

It is always possible the policies were missold, in which case even the bank admits it might have a problem.

But if the intent was to avoid taxes, as appears to be the case in some instances, customers can hardly be compensated for trying it on and getting caught. If they weren't aware of the rules, they should have been.

After all, how many people have £140,000-plus to invest without bothering to check the small print . . .?