Kenya's interior ministry has said it has not renewed the licenses of 27 betting companies including the country's biggest, SportPesa.
In a letter to telecoms company Safaricom, the government says that the companies have not met the "outstanding renewal requirements". But, correspondents say, it is not clear what exactly these requirements are. SportPesa is known worldwide as a sponsor of English Premier League clubs.
The company's name currently appears on Everton shirts. Most people in Kenya who want to gamble use their mobile phones to place bets. The government has asked Safaricom to suspend the betting companies' telephone short codes. In a response through its lawyer, Safaricom says its estimated 12 million clients should still have access to the funds they have deposited in their betting accounts.
It has asked for permission to keep the short codes to allow people to withdraw the money. In addition, it points out that SportPesa has an outstanding court case with the authorities on a previous ruling. It has also asked the government to make a public announcement about the ruling on the licenses.
Gambling has become big business in the country in recent years as companies have taken advantage of technology that makes it easier to sell their services. Some have expressed concern that a growing number of young people are spending their money on gambling.