Sorry to hear about this, I had the same on my previous car but unfortunately the offender decided to leave without providing any details.
Any accident whether that be fault/part-blame/non fault, will impact your premiums (generally in that order of cost). There is no hard and fast rule. Believe me, I've been in the Industry for 7 years and I've seen claims make no difference and I've seen claims make insane differences. It just depends on the overall risk, EG:
17 year old pays £2000 at year 1, has a fault accident, renewal premium is sent out at £4000. He/she shops around and see's a quote for £2200
45 year old with 9 years protected NCB pays £350 at year 1, has a fault accident, renewal premium is sent out at £420. Shops around and finds a price of £360
45 year old with 9 years NCB unprotected pays £320 at year 1, has a fault accident, NCB is reduced to 3 years for renewal, renewal premium is sent out at £540. Shops around and finds a price for £400
It really is so variable it's almost pointless discussing it.