I suspect this was the HS-125 used by Osama Bin Laden when he used to visit Formula One Grand Prix in his playboy days in the late 1970s, early 1980s

His construction business was one of the partner sponsors to Saudia on the Williams Grand Prix cars of the era. Interesting to note that these cars, now immaculately restored for historic racing, somehow seem to have an oversight on that bit of their livery!

A quick search found a picture of the aeroplane ‘as was’ here: http://www.abpic.co.uk/photo/1194634/