Could I ask where this £250m figure is coming from?
The BRFC accounts to 30/6/17 show £94.8m owing to the Parent Company (Venkys London Limited). They also show £146.9m share capital. But £134m of this share capital was already in place before Venkys bought the club. Therefore I calculate their total investment to be £94.8 + 146.9 -134 = around £ 108m.
The Venkys London Accounts show that at 30/6/17 the total share capital was £132m. I cannot find any evidence that the Raos have put any money directly into BRFC - it has all gone through VLL therefore their maximum investment must be the £132m VLL share capital. I'm not sure what the difference between the 108 and the 132 is but maybe its the £23m they actually paid for the club.
In summary, my understanding of the published accounts is that all the funding for BRFC has gone via Venkys London Limited and since at 30/6/17 it had £132m share capital, this £132m is the maximum they had put in at that date.