Hergé: Christopher Tayler article in "London Review of Books", June 2012

The London Review of Books, Vol. 34 No. 11, published 7 June 2012, has an article "Haddock blows his top" by Christopher Tayler in which he reviews Pierre Assouline's Hergé: The Man Who Created Tintin and Benoît Peeter's, Hergé, Son of Tintin.

Actually it focuses mainly on Hergé's life and the charges of anti-semitism made against him before and during the war, though Tayler makes the interesting remark that Sakharine of Unicorn was a Russian Jew, which is born out by his business card which features the typically Russian given name Ivan Ivanovitch.

It also mentions publisher Raymond Leblanc's fury when he discovered that Hergé was employing former collaborators such as Robert Poulet.

In the opening paragraph Tayler compares Hergé to T.S. Eliot. It's quite fun the comparisons he comes up with, though I myself haven't read much of Eliot's work (beyond Old Possum's Book of Practical Cats).

I see that the article is now availabe to read on line, for free, whereas it was behind a paywall when the above was posted. The LRB allows you a free article (possibly one a month) before you have to even create an account, so it's not a bad deal!
Here's the link <a href="https://www.lrb.co.uk/the-paper/v34/n11/christopher-tayler/haddock-blows-his-top" target="_blank" rel="ugc">to the article itself</a> - I don't know if it will work for you, but if that fails you can search for it using the details given above, and get in that way.

Hmmm... Reading the actual article, you've added a degree of certainty to something which Tayler simply conjours out of thin air as a vague possibility.
He says of Sakharine "...a sinister-seeming, possibly Russian-Jewish character turns out to be a goodie after all..."; there's nothing about "Ivan Ivanovitch" being a Jewish name.
It is a typically - even stereotypically - Russian name, to the point that it seems to be the equivalent of "John Smith" or "John Doe", used as an all-purpose default name (it was the name given by the Russians to the dummy astronaut used in testing Vostok space-craft, for example). But that's not really enough to establish more than a possible heritage for the character (as I have said before, I have an Irish name, but I am not Irish).
How he (Tayler) came to the conclusion that Sakharine was meant to be Semitic is never stated.
It's made more complicated by the fact he is using Sakharine's supposed Jewishness, and position as a possible-baddie-who-turns-out-to-be-a-goodie, as a potential refutation of charges of anti-Semitism, then muddies the waters when mentioning that Spielberg's movie makes him into the actual baddie, which would be unfortunate if Sakharine were to be Jewish, as Speilberg is himself both Jewish and a vocal protector of Jewish culture, speaking out against anti-Semitism through endeavours such as the Shoah Foundation...
I'd surmise that, if Spielberg was happy to have Sakharine as the actual villain, then he wasn't seeing him as a Jewish (or Semitic) stereotype, which, sort of negates the need to rehabilitate the character in any way.