According to the paper, the capital's PR firms are earning millions of pounds a year promoting 'foreign regimes with some of the worst human rights records'.
On a map purporting to show all UK firms currently working for foreign governments, Bell Pottinger and Hill & Knowlton jointly make more appearances than the rest of the agency world combined.
The two agencies are standing firm. 'I am not an international ethics body,' retorted Chime Communications founder Lord Bell.
Some in PR circles have privately objected to the tone of the reporting, but The Guardian is unquestionably justified in shining a torch of transparency into this burgeoning area of PR.
Whether the increasing millions trickling into the industry from overseas governments is a cause for concern remains a matter for robust debate.
In this instance, many consultants will understandably object to any PR activity that seeks to defend or deflect attention away from a country's human rights abuses.
Yet international PR assistance need not equate to burnishing a rotten regime. As many NGO comms chiefs will testify, there are times when you have to engage to make progress - particularly in transitionary situations. And by highlighting the positive aspects of a developing nation, one can help to promote trade or to boost tourism, which may in turn open up the country to greater scrutiny.
Objecting to PR on the basis of the causes it serves can quickly lead one down a cul-de-sac. The main problem with this approach is that no two people can agree on what is acceptable or where to draw the line.
Ultimately, few would disagree that questionable overseas regimes are entitled to exercise freedom of expression, in the same way that Amnesty International and others are entitled to deploy their PR resources to argue against that country's record.
If a PR agency then chooses to step into the breach, they must accept that their reputation may take a hit - rightly or wrongly.