Father Denied Any Partnership In Shop

My Father worked in a ready made kids garment shop, it was typically purchased by his 3 brothers, (They purchased the shop) and added my father as a proprieter in the firm. My Father honestly worked there for 27 years and finally the 3 brothers decided to give away the shop. They denied my father any partnership or any settlement amount, they never looked after the shop but were always ahead in accepting the profits.
Could some one provide a legal advice of the laws related to this scenario? What should we do, the three brothers deny the partnership claim since my fathers name wasnt on the purchase document.
Any help would be highly appreciated.
Thanks,
MV

Dear Cabba,
Kindly provide the below details for more clearity.
1. Who is the sole owner..? names on purchased documents or land documents.?
2. name of propriters in all legal documents..?
3. is there any partnership deed..?
4. how much % of share each one & what is the payment mode of share..?
Regards,
Tushar Swar

Hello MV,
Further to the queries Tushar Swar mentioned, pl confirm the type of remuneration your father was being paid for the 27 yrs--was it a flat salary OR any share in the monthly/annual profits?
Also, you mentioned "added my father as a proprieter in the firm"--was it informally OR was there any document?
And, who used to handle the Statutory obligations like Sales Tax, etc--ON PAPER?
Suggest as much details as possible--this will enable the members to give more accurate & practical suggestions.
Rgds,
TS

Mv
though its very unfortunate, only upon perusal of clauses in agreements related to profit sharing, liability & liquidity, claims shall be seeked. So approach a lawyer with relevant docs.