The Gambling Commission has warned operators over the use of gagging orders.
This follows a series of incidents where consumers have been paid in exchange for not discussing their experiences with the regulator.
The Gambling Commission announced it was fully aware companies had been including non-disclosure clauses within settlements with consumers.
Ladbrokes had previously agreed to pay out almost £1m to victims of a gambling addict who had stolen money from others to place bets, according to reports.
Five victims directly complained to Ladbrokes about accepting stolen funds and the bookmaker made the decision to pay them just short of £1m.
Lawyer Peter Coyle also spoke exclusively to Gambling Insider in November about Betfred offering £2,500 ($3,700) to reimburse the costs of a customer's jackpot celebrations. This settlement offer included an additional £60,000 – which came with a non-disclosure agreement – after he was refused a £1.7m jackpot .
The watchdog said: "Some of these agreements may have had the effect of preventing those consumers from reporting regulatory concerns to us, by either excluding disclosure to any third party or, in some cases, explicitly preventing customers from contacting the Gambling Commission."