There's a partnership firm having 3 working (A,B, C) & 1 non working partner (D). Out of these 3 (A, B, D) are real brother & sisters. One of the main partners (A) forms a propretorship firm in name of his brother who is one of the working partners (B) without consent of partner (C). No agreement exists between the partnership firm & the Proprietorship firm.
Should this proprietorship firm be called a Sister Concern and the partner C (whose consent was not taken) shall be held liable for any legal action on the proprietorship firm ? Both the firms are operating from the same premises.