Phuket police and Royal Thai Navy personnel were delivering the ultimatum to Thai Xin Ya Zhou Tour (Thailand) Co Ltd, whose 40 or so buses are regularly seen carrying tourists around the holiday island.
According to the operators of about 10 Phuket businesses - including Simon Cabaret, Aphrodite Cabaret and Sea Star Tour - a change in management at the Chinese company has led to them severing all connections with their former business partners.
''What we have been told is that we will need to seek the money we are owed from the people who were previously behind Thai Xin Ya Zhou Tour,'' said Keangsak Klongsamut, marketing manager at Sea Tour.
He said that Sea Tour was owed five million baht, accumulated since April, although the change at the top of the Chinese business took place in June. About 40 million baht in invoices to Phuket companies was outstanding, he added.
There was great alarm because it was believed that the ''new'' Thai Xin Ya Zhou Tour was buying its own boats and restaurants and looking at investing in its own resort, Khun Keangsak said.
Thai Xin Ya Zhou Tour operates throughout Thailand, not just on Phuket.
Today's investigation by police and the Royal Thai Navy also involves Santi Pawai, chief of the Ministry of Tourism and Sports and now taking a serious approach to his new role as Director of the Business and Guide Registration Branch.
With a crackdown underway, the Chinese business may have chosen the wrong time to change investors and neglect to cover outstanding debts.
The companies who are owed money are anxious to achieve an outcome that allows them to recover what they are owed. Officials were hoping to be able to quickly mediate the dispute with quick payment of the outstanding debts.
In the broader context, officials are concerned that a change of this kind within Thai Xin Ya Zhou Tour could also be attempted by Russian and Korean companies who also cater to large numbers of package tourists.