The Independent Betting Adjudication Service (IBAS) could force Ladbrokes to pay out on hundreds of bets which its trading team turned down.
According to reports, IBAS is looking specifically into three online cases where bets were referred to Ladbrokes traders to decide whether or not to accept them.
A high number of wagers, predominately on racing, are referred to traders in which they are often declined or re-offered, either reducing the odds or stake.
The three cases being investigated all received an official "bet number." This appeared to be an indication they had actually been accepted at some point by a trader.
It wasn’t until after the races had finished that each case was "cancelled."
If IBAS sides with the players, all customers of Ladbrokes who have faced similar issues in recent months when attempting to place a bet and been referred to a trader for approval could be entitled to a payout.
There is likely to be a cap on the amount issued to each customer, to prevent the operator being hit with a significant loss.