Join the club.   You are not the first.  The same thing happened to me and
Peugeot's answer is to replace everything from the tank to the injectors at
a price (quoted by my local dealer two years ago when mine went) of £3,500.
In the event a local mechanic did it by cleaning rather than replacing and I
was fortunate that the particles had not got past the filter.   That cost me
£800.    Other people on this group have had the same problem, it seems to
be an HDI thing.   Mine was 5 years old and at 92,000 miles so I could not
really complain but since then I have seen people at under 30,000 some have
even been early enough to be done under warranty.

i wonder if anyone could possible help me???? I have just put my car
(Peugeot 406 hdi 90) in for a diagnostic report. The fault that was
found was a high pressure pump it was stripped and examined and the
mechanic found metal particles in the fuel system, it requires a high
pressure fuel pump and complete fuel system, I have been informed that
this is a manufacturers problem, I have been quoted £1100 with no
guarantee that this problem will not recur, as this is a design fault I
see no reason why I should bear the cost for a fault that is not of my
doing, is ther eanyone out there anyone who can possible enlighten me :(

It is a fault in the fuel lift pump in the tank. The bearings were clearly
badly designed, and you get little bits of bearing metal getting into the
fuel system. How these get through the fuel filter, I do not know, but if
they do then they can damage the high pressure pump, and even the injectors.
So the only safe way to deal with this is to replace the lot, though it
might be possible to strip and clean components, and just replace the lift
pump.
I hope they have redesigned the lift pump by now, so a replacement should be
more reliable. (I have a 307 HDI, which is so far OK).