From reading your response to Colin Berry from today’s blog (15/Nov 2013) I was reminded of a documentary about Tutankhamun ("Secrets of the dead") arguing that embalming oils combined with oxygen and linen could have caused a chemical reaction which "cooked" the king’s body at temperatures of more than 200C.
Here’s a link: [CLICK HERE]
They talk about spontaneous combustion about 50 min into the program.
You may recall that the PBS Secrets of the Dead series did a program on the Shroud of Turin. Although you can watch almost any of the programs, online, the one about the Shroud does not seem to be available except by purchase. But there is much to read about the shroud on the PBS site.