The Betting Control and Licensing Board (BCLB) has ordered Airtel to shut down the playbill numbers of betting firms whose licences it has not renewed.
The action comes a week after it gave a similar directive to Safaricom, banks and the Communication Authority of Kenya in a move that threatens the Sh200 billion betting industry.
Airtel, the second largest mobile service provider, had continued to operate playbill numbers of betting firms a week into the crackdown.
"We wish to inform you that the licences for the following companies were not renewed, until they meet the outstanding renewal requirements as well as outcome of ongoing due diligence to determine if they are fit and proper to hold a licence from this board," BCLB acting managing director Liti Wambua said. The letter dated July 15 is addressed to Airtel Money Director Vincent Wakaba.
"Consequently, we request you to suspend their playbills and short codes until otherwise advised," BCLB said.
"Meanwhile, allow your customers who may be affected to withdraw their deposits before Friday 19 July, 2019, and as a matter of good faith, we will appreciate if you share with this office the number of people who will have withdrawn their money and the total amount thereof," Mr Wambua said.
The board falls under the Interior ministry and has been implementing the government directive to disable the operations of 27 betting firms.
It is not clear why it did not write to the firm at the same time it did the other players in the market.
The top betting firms have moved to court, escalating their row with BCLB.
SportPesa has sued the government, seeking compensation for the days it has been out of business after BCLB ordered Safaricom to shut down betting companies' playbill numbers and short codes.
Its rival, Betin Kenya, say the July 12 switch-off of their playbill numbers and short codes is illegal because they have court orders allowing them to continue operating, despite being denied licences by the government.
Both firms want the suspension of their payment systems lifted, and the chairman and top executives of BCLB jailed or fined for ordering the switch-off, despite the court order.
They also want the court to quash a notice by BCLB ordering Safaricom to disable their short codes and paybills.
Betting firms insist they have complied with all the relevant laws and tax requirements.
Some have even shown their tax compliance certificates as proof, terming the government action malicious.
The crackdown captured the attention of the British Parliament on Wednesday. One legislator asked the government what assessment it had made of the role of British gambling companies and football clubs in encouraging children in Africa to gamble illegally.
The Parliamentary Under-Secretary of State, Department for Digital, Culture, Media and Sport, Lord (Henry) Ashton of Hyde, said the Gambling Commission expects operators that it licences to obey the law in other jurisdictions in which they operate.
Baroness (Shaista) Sheehan said companies with British links use techniques banned in the UK to appeal to African youths by using cartoon characters and free branded merchandise.