Gambling Commission CEO Neil McArthur says the level of compliance among UK-facing operators based in Malta is currently "not good enough."
Referencing the outcome of Commission research from 2018, McArthur said 45 of 123 online operators were told to submit an action plan to raise compliance standards.
A further 14 were the subject of enforcement investigations, while seven operators have paid £18m ($23.2m) in penalty packages and five have surrendered their licenses.
McArthur said: "The Commission is clear that although progress has been made in the regulation of the online market since 2014, far more needs to be done to raise standards.
"So let today be the start of a fresh commitment: a commitment to raise standards and to collaborate with us to make more progress more quickly.
"In return, the Commission commits that we stand ready to help in these efforts. But, rest assured, we also remain ready when needed to take enforcement action."
Gambling Insider’s annual Malta Focus publication will be live and in print in November, exploring the issue of compliance in greater detail.