Tesco Lotus, a subsidiary of multinational retailer Tesco, is suing Kamol Kamoltrakul, a Thai commentator and academic for his attacks on the chain's expansion within Thailand.
Can you say "libel chill"?
Tesco has been operating in Thailand for a decade. In addition to the 370 stores it already operates, it planned to open a further 162 in 2007-8, according to its annual review published on its website.
Mr Kamol says the suit filed against him concerns an article he penned for Bangkokbiznews on 29 October, in which he claimed superstores were driving out local so-called "Mom-and-Pop" stores and threatened to ruin the fortunes of millions of Thais.
In the same article, Mr Kamol alleged Tesco was guilty of so-called "creative accounting" - the practice of creating complex accounting structures which permit the lowest possible level of tax to be paid.
He also claimed that Tesco's Thailand operation provided the company with 37% of its global income.
Mr Kamol now admits he was mistaken in the last allegation, acknowledging that the true figure is closer to 3.7%.
But he says Tesco is exploiting his error in order to "scare other journalists".
"I was shocked that I was sued for this amount of money," Mr Kamol - a neat, bespectacled, softly-spoken man in his late 50s - told the BBC News website. (Note: Tesco wants more than $3 million in damages - BD).
"It's nonsense. Tesco know I don't have that kind of money, so why do they do it? The only thing I can think is that they want to silence me."
Mr Kamol says he is worried Tesco could win - and says that if they do, under Thai law he could lose his home.
Kamol is visiting the UK at the behest of Index on Censorship.
He's in good company; Tesco is also suing the Guardian newspaper over articles it ran suggesting the company was excessively creative in avoiding taxes.
The Beeb printed the following statement from Tesco:
"Tesco does not have a policy of using legal action to silence its critics. In fact until now we have never had to resort to legal proceedings to defend our reputation."
'Deeply misleading'
"The ongoing cases in Thailand and the UK are entirely unrelated. Neither has anything to do with restricting free speech and it would be deeply misleading to suggest they do. The right to free speech does not of course imply the right to defame us," Tesco said.
"In Thailand, Tesco Lotus has been seriously defamed in a sustained and malicious campaign over a number of months.
"In the UK, The Guardian made a series of very damaging allegations relating to Tesco's tax affairs despite our clear indications to the paper in advance that these were utterly false and that we would defend our reputation if necessary. The Guardian was given the opportunity to retract the allegations but chose not to do so.
"In both cases we have been left no option other than to take legal action - a step we would not consider unless we believed it was entirely justified. We still hope the matters can be resolved by agreement, but if not we will have to resort to the courts to restore our reputation."