It is not a rumor, it is indeed a fact.
When this repackaged stuff was introduced to the market in 2016, it was indeed old, expired leftover stock of long discontinued Aviphot Pan 400. Last coating run of Aviphot Pan 400 at Agfa in Mortsel was already in 2008.
This expired film rests were already detoriated (probably of bad storage at the source bought) and had very high base fog and reduced film speed.
Experienced long-term users of Aviphot Pan 400 (e.g. aerial photographers and traffic surveillance film experts like SPUR in Germany; and film enthusiasts like me and lots of others here on photrio and other film forums, especially in Europe, and facebook photo groups) immediately realized after detailed film tests of Street Pan 400 what this film really was originally.
And those who reported their test results publicly were massively attacked and bashed by Bellamy Hunt for telling the truth.
Because Hunt has told to his customers the marketing fairy tale that the film was "freshly produced" and "exclusively for him", and has "never been on the market". All that nonsense to fool his customers and to hide the scam that it was just old, discontinued, expired film offered at insane high price.
And when this first leftover stock was sold, he just switched to Aviphot Pan 200. Of course without any information to his customers. And with the same ridiculous high price (much higher than all other Aviphot Pan 200 repackaged offerings).