Indesit G75C, Drum not turning?

Our dryer has been making a noise for a couple of weeks, certainly sounding a lot louder when it has been on, almost as though there are heavy items within the drum.

The drum then ceased to turn and was buzzing, almost as though the motor was trying to turn it but is being impeded. I forced the drum and it spun again for maybe another 10 minutes before stopping and just buzzing.

I don't think the belt has gone as I am still unable to turn the drum, and it remains in one position and will not budge even being pushed with considerable force.

I've read somewhere it could be the bearings, though I'm not convinced it's this?

The other thing i need to add is that when i finally got to examining the dryer, there was and abundance of lint and fluff stuck inside the actual dryer (which i know is a fire hazard!)

Is it possible that there could be a build up of fluff stopping the drum from turning (I haven't been able to get they dryer apart yet; I just had a look in side the front so far)?

Any help would be greatly appreciated.