Mined blocks reappearing, no drops.

When I mine blocks they don't drop and reappear instantly. I've tried this on clay, sand, dirt, wood, vines and pumpkins. Bamboo, flowers and drops from killed mobs seem unaffected.

I have just done a long stint in the Nether, where I was able to mine freely, the bug only occurred after I returned. I am able to place objects with no issues.

I have no mods of any kind installed, tried using the /gamemode command to reset my game to Survival mode in case it had somehow gone into adventure mode, this had no effect.

This one is a gamebreaker, so a prompt fix would be fantastic!