Is this actually the case, I've never heard of it, perhaps a few Lab breeders would comment.

https://www.donedeal.ie/dogs-for-sale/labrador/25449346

Cross breed.. or more than that.  The pups look more Dobermann than Labrador. Lol
Labs come in 3 colours yellow, black and chocolate (liver to some)

Interestingly rhe chip isn't registered anywhere in Europe

Yes you can get black and tan popping up, however it's not common, and I couldn't even begin to explain the colour genetics behind it.  However, that pup doesn't look full Labrador to me, it looks part hound by the ears and domed head?

Not a Lab breeder, but I do know a bit about colour genetics. Apparently most labs are genetically black and tan but that gets “covered up” by dominant black (Kb). A different gene can turn the black into chocolate (bb) and either can in turn can be changed into yellow (ee).

You’d need a copy of the Ky gene from each parent to allow pattern expression like tan point (or saddle, sable or agouti/wolf grey) so I’d suggest that if this came from crossing it would most likely be that both parents were crosses of some kind.

I don’t know specifically about Labs but I guess it’s possible for Ky to just spontaneously turn up in a purebred line, but again you’d need both parents to carry it.

Looks mix (if that's a parent, ditto), even if black and tan Labradors can appear?

That's exactly what I have been reading silver leaf. Colour genetics are fascinating

It’s definitely a thing in purebred labs. Tanpoint and brindlepoint. Quite nice looking dogs imo, not that you’d breed them deliberately. Could be purebred, could be mixes.

http://www.labradorretrieverguide.com/black-and-tan-labradors/

Scrolling down that article, I found the above.   I still don't see the dogs pictured as Labradors.   Interesting is the idea about the connection to Gordon Setters in the back ground.
"The “black and tan” trait of the Labrador is believed to be from Gordon Setters, which are one of the dogs interbred with the St. John’s Water Dogs – the ancestors of Labradors."   From the article linked to above.

One of those pictures is Corrib Kai a well known/used FT stud dog....never heard of any mismarked pups from him

> Not a Lab breeder, but I do know a bit about colour genetics. Apparently most labs are genetically black and tan but that gets “covered up” by dominant black (Kb). A different gene can turn the black into chocolate (bb) and either can in turn can be changed into yellow (ee). You’d need a copy of the Ky gene from each parent to allow pattern expression like tan point (or saddle, sable or agouti/wolf grey) so I’d suggest that if this came from crossing it would most likely be that both parents were crosses of some kind. I don’t know specifically about Labs but I guess it’s possible for Ky to just spontaneously turn up in a purebred line, but again you’d need both parents to carry it.

yes, looking at some of results on mydogdna, seems the majority of the public labs have two copies of the tan gene with some having one tan and one recessive black gene. While for the dominant black gene I did find five who only had one copy of the gene, the gene has a 93.68% frequency for the breed. Some just mentioned they had the one while others also mentioned bridle. Only one of the dogs was registered though.