Yes, this question has already been asked here. This time, however, I was wondering if anyone can point to official LEGO web page on which this fact is confirmed. I've already read "Fair Play" document and "Fair Play Brochure" but all what they say is that "the LEGO logo is a trade mark and cannot be used w/o permission" meaning that if I have a brick with LEGO logo on it then I can be 99,99% sure that this is a genuine LEGO brick. What I need, however, is the "opposite" i.e. a sentence claiming that "a stud on a genuine LEGO brick has always had the LEGO logo since the year 19xx" or even more: "a stud on a genuine LEGO brick has never had this round cavity on the top" (cavities I mention are present e.g. on studs here).
I've already asked the same question via the contact form on the official LEGO support page but received no answer yet.
Context: I'm currently having a dispute whether a set of bricks that some guy sold me were genuine LEGO bricks. He claims that they were, I know that they were not. I will, however, have to provide evidence to the police. Information on lego.com page or answer from lego.com would do in my opinion. High resolution images of the 42009 set (battery part) on official LEGO page would also be good but
this set is no longer present on lego.com this set does not have the close up of the part I need. High resolution images of 8293 (Power Functions Motor Set) are there but are they a proof I don't know yet (one can always say that these parts have LOGO lego now but they didn't in 2013). There is a movie with 42009 on lego.com but it is rendered and does not present real bricks and not sure if can be used.
EDIT: yes, all the pieces of the brick set I received (the supposed 42009 set) are forged. I can tell this because the bricks I received differ in many aspects from bricks from original LEGO sets I've assembled so far (more than a dozen sets, mostly > 1000 bricks): some of them connect poorly, some of them connect so hard I struggled a lot to disconnect; the surface of liftarms is not as straight as LEGO liftarms; the liftarms have this extra filling around holes (google "lepin liftarm" and choose "large images" in "adv search" to see what I mean); some pieces are not cut properly e.g. the bushes have thin pieces of plastic connected to the hole on the side; and the main one: there is no LEGO logo on any of the parts: not only the studs but also the battery box and motor. However from legal point of view I can't just say that I am sure that these are not LEGO bricks. Moreover I cannot even prove that the bricks I present are indeed the bricks that the other guy sent me. So I took a closer look at the pictures from the auction (the pictures the seller made himself = the pictures of actual brick set he sent me) and found pieces with studs with no LEGO logo (Black Plate 2x3 (3021) , Motor 9V Power Functions L (99499c01) ). I was extremely lucky that this seller made pictures with such high resolution. And yes, I contacted the LEGO support and sent them exacly the same pictures as below and they confirm that these are NOT original LEGO bricks. I will post their full answer and some more content soon.