Alternator full of grease and dirt - sabotage?

[Anton17]

Following up on a previous post of electrical faults on my Honda NSR 125 2001 (battery won't charge), the garage has came back and had a look at the alternator/generator. They took the case of and the whole thing was filled with shit - thick black grease type stuff with what looked like sand and dirt.

They said it could be possible that someone had known what the problem was and caked the alternator full of this stuff to act as an electrical mask so it showed positive readings in test. Sabotage, in other words. Has anyone ever heard of anything like this?

The mechanics can't work out where this stuff has came from since with the case on and sealed nothing should be able to get in. I've only just bought the bike so I don't know what has happened and can't trace it back. It sounds like a pretty peculiar thing and was wondering if anyone has heard of or had any experience with something similar or has any idea where the substance has came from? We can only surmise it's either been botched as a mask by someone who knows what they're doing or the casing has been left off through the weather.

Any ideas?