Corrosion of Bearing in an oil bath

[HMMG]

I have observed that one bearing is mounted on a hollow shaft trough which insulated lead wires are running through to supply power to an internally built electric motor is getting rusted. The bearing is inside an enclosure that is sealed and runs in a gear oil bath.
I am not sure if the current passing in those leads would have an effect.
I hope that someone may had a similar experience or have explanation on this.