Chinese mobile-security software maker NQ Mobile Inc's Chief Financial Officer KB Teo resigned, citing family reasons, amid a buyout offer and a delay in filing its annual report.
The company's shares fell as much as 13 percent in early trading on the Nasdaq.
NQ Mobile said Teo's resignation, effective Aug. 22, was not related to the company's operations, policies or accounting practices.
The company has faced repeated allegations of fraud from short-seller Muddy Waters Research Group. The company dismissed its independent auditor, PricewaterhouseCoopers Zhong Tian LLP, in July.
The chairwoman of NQ Mobile board's audit committee, Ying Han, stepped down in July, citing personal reasons.
NQ Mobile said on Friday it was confident of the accuracy of all its previously reported financial reports and filings.
Albert Fried & Co analyst Sachin Shah said Teo could have left after the company filed its results, which have already been delayed.
"That would have been the best case scenario. It's very hard for the market to digest that he is leaving for personal reasons in light of the fact that there is pending work," he told Reuters.
The company, which was due to file its annual report in May, said it needed additional time to file the report.
Teo joined NQ Mobile as chief financial officer in September 2013. He was the lead banker for NQ Mobile's initial public offering on the New York Stock Exchange in 2011, according to a profile on the company website.
Vincent Wenyong Shi, the company's co-founder and chief operating officer, will be acting chief financial officer, NQ Mobile said.
NQ Mobile received a buyout offer last month from investment firm Bison Capital Holding Co for about $490 million, after the company sold a small stake in its unit, FL Mobile, to Bison in May.
NQ Mobile's shares were down 1.4 percent at $6.32.
(This version of the story was refiled to correct advisory to remove reference to Muddy Waters comment)
(Reporting by Abhirup Roy and Soham Chatterjee in Bangalore; Editing by Don Sebastian)