Snap's chief strategy officer, Imran Khan, is leaving after three years with the company.
According to a filing with the U.S. Securities and Exchange Commission, Khan will continue in his role for an interim period before stepping down "to assist with an effective transition of his duties and responsibilities." No date has been set for his eventual exit.
"After nearly four years at Snap, I have decided to step down," Khan said in an email to staff obtained by CNBC. "This has been a very difficult decision for me to make. There is never a perfect time to say goodbye, but I know that the time is now. We have a stellar leadership team in place to guide Snap through the next phase of growth and on to the next chapter."
According to the SEC filing, Khan's departure is not related to any disagreements over Snap's accounting, strategy, management or policies.
"Imran has been a great partner building our business," Evan Spiegel, Snap's chief executive, said in a statement. "We appreciate all of his hard work and wish him the best."
Snap's share price fell 1.5 percent in U.S. premarket trading.
The company has been met with mixed sentiment from Wall Street over disappointing financial results and a drop in user numbers.
The Snapchat parent's most recent quarterly results beat estimates, but the company issued lower-than-expected revenue guidance. Daily active users (DAUs) on the platform fell to 188 million from 191 million in the previous quarter.
"I think Mr Khan is likely the sacrificial lamb as a result of the negative user stats since the app redesign earlier this year," Neil Campling, co-head of global thematic group at Mirabaud Securities, told CNBC in an email.
He added: "Snap hasn't yet reached scale in advertising revenue and strong daily engagement is required to give the company leverage with advertisers. Until improvements are seen in the DAU stats and proof of improving engagement, Snap's stock will continue to struggle."
A recent revamp of its social network, where users can document their day with pictures and videos that stay up for 24 hours, was mostly unpopular with users, leading the company to alter the platform yet again.
The main contention was with Snap's prioritizing of content by publishers and content creators, rather than content generated by friends. Snap rowed back slightly on its initial overhaul of the app which moved friend-generated stories to a "Friends" section on the app, by shifting it back into the main section called "Discover."
The company is also facing increased competition from the likes of Facebook and its photo and video-sharing service Instagram. Both of these social networks have their own versions of Snapchat's "story" feature.
Instagram heated up the competition in June with a long-form video format called Instagram TV (IGTV). The service lets users upload and view clips that are up to 60 minutes long.
Although the firm could find comfort from figures that show younger users might in fact be leaving Facebook for Snapchat. New York-based marketing research firm eMarketer expects Facebook to lose 2 million users under the age of 25 this year and Snapchat to pick up 1.9 million users within that age bracket.
- CNBC's Sally Shin contributed to this report.
Disclosure: CNBC parent NBCUniversal is an investor in Snap.