"As at the date of this announcement, the company has failed to repay the outstanding facility to HSBC. The company is assessing the impact of the default on other loan facilities, which may trigger cross-default, which may in turn have a material adverse impact on the financial position of the company," Kaisa said.

Given the HSBC loan default, it was highly likely that other banks that had lent Kaisa money and bondholders would demand immediate repayment, said an analyst.

"Other banks are likely to call in their loans. Otherwise, there may be nothing left in the company for them. No bank would probably want to give Kaisa financing because the company's future is uncertain," the analyst said.

Kaisa had issued a number of high-yield bonds and it was common for such bonds to contain a covenant granting bondholders the right to call for repayment if the company defaulted on other loans, he said.

HSBC's call for repayment was due to a mandatory pre-payment provision triggered by the resignation of Kwok Ying-shing as chairman, Kaisa said.

On December 10 last year, the company said Kwok would resign as chairman and executive director at the end of the year, citing health reasons. But rumours persist of him being investigated by mainland authorities even after the firm's denial in October that he had been detained.

"If there is a change of management, it can trigger a covenant where the bank has the right to ask for immediate repayment … A change in management can change the operations and financial profile of the company," the analyst said.

Making the problem worse was the recent resignation of several top executives, he added.

The chairman's brother, Kwok Ying-chi, resigned as non-executive director on Wednesday, only days after Kaisa said he was to be demoted from vice-chairman. Two days before that, another vice-chairman, Tam Lai-ling, and chief financial officer Cheung Hung-kwong resigned.

"If the top management is gone, banks will be uncertain whether the company will continue to be the same as before," said the analyst.

In a report last month, Haitong Securities likened the resignation of Kwok Ying-shing to a cancer that had to be cut off from the company. In another report a few days later, it said: "We reiterate our sell rating for Kaisa, considering its escalating trouble in Shenzhen, causing higher uncertainties ahead."

All of Kaisa's property projects in Shenzhen had been restricted or suspended, Haitong said. "Clearly, the authorities' move is trying to paralyse the company's entire operations in the city. As Kaisa's hometown, Shenzhen has been the largest contributor of revenue and profit," it said.