Anyway, I did a bit of researching this morning. According to Kevin who works for Channel 5 it was a documentary that they "re-versioned" based on a documentary on the Discovery Channel, called "Ramsees:Wrath of God or Man?". There is a trailer for it here. There's also a number of interesting featurettes, which shed quite a bit of light on the film.
In the brief segment I saw they touched on the existence of the Apiru and related them to the Hebrews (with perhaps a little too much conclusiveness for such a vague mention)and swiftly moved onto the heart of the show - the alleged discovery of the tomb of Ramsees.
Two things stood out in particular. Firstly, there were a number of dramatised segments from the bible. Mostly rather standard - Ramsees and his dead son, the angel of the Lord creeping round Egypt Ã la The Ten Commandments (1956), but one was a "god shot" looking down on the Israelites as they passed through the walls of the Red Sea which was quite interesting. From the previews it appears that this is was quite a major feature of the film.
Secondly, the documentary was pointing out how the Ramsees son is never given an age in Exodus - in fact he could have been an adult when he was killed. I must admit that is one thing I had never considered. I'm fairly confident that all the Moses films show him as a boy, and I know of no other dramatisation that deviate from this norm. Elsewhere I have argued that The Ten Commandments (1956) is now thelense through which the story of Moses is viewed, and I suspect that before that it was DeMille's earlier, if truncated, version of events, The Ten Commandments (1923) that held sway. This certainly seems to be the case here. It is hard to imagine an adult son of Ramsees. Furthermore the scenes noted above all seem to be strongly influenced by The Ten Commandments. The boy being laid down looks very similar to a scene from the film, I've already noted how the Angel of the Lord scene apes its predecessor, and even the impressive overhead shot, relies far more on DeMille's Red Sea as opposed to scripture's shallow sounding "reed sea".
As for the documentary itself, it's point, going by the aforementioned trailer, seems to be that Ramsees's son had grown up to be an adult, and had been killed by human, rather than divine, means. I have heard some people speculate that the first born of Israel were killed in a sacrificial attempt to gain the favour of their gods (and I can only guess that this is where Egyptologist Kent Weeks' theory was headed), and it does have some plausibility. However, an awful lot rests on the pharaoh in question being Ramsees. This it appears is far from certain. The background info on Ramsees (200 wives, 150 children) was certainly interesting though.
The film goes on to reconstruct both the faces of Ramsees and of the skull they think might be his first born child. There's perhaps some similarity, but there also appears to be some similarity to the face of Jesus re-constructed by the Son of God documentary a few years ago.
There's a whole section on the show at the Discovery Channel website, and some interesting discussion here, as well as Gary Demarr's article about the documentary film