Lead rot? Help!

[.:Gunslinger:.]

Hi guys,

I unpacked some minis I bought over a forum and proceeded to wash them (warm water+dish washing soap), before the washing they were shiny new white metal, now some of them (not all!) have nasty dark spots on them were the metal seems to be corroded:

Image

I don't know what happened! Has anyone seen something like this before? I fear it could be the dreaded "lead rod" which woud mean I had to trow it all away... :sad:

Please help me out!