Clunk from steering?

I've developed a strange clunk noise from the steering the last few days and I'm wondering if anyone has had the same fault in the past.

It's more noticeable when stationary (probably due to the amount of lock required) but at almost full lock there's a strange clunk. It happens in both directions.

Initially it sounded like it was inside the car and my suspicion was the steering colum.

But now it sounds like it's near the bulkhead?

It seems louder inside the car, but I've only had the chance once to be outside the car whilst looking for the noise.

Anyone else had anything like this before?

It's an 08 vrs Diesel with 47k on the clock if it helps.