Wilke has headed Amazon's worldwide consumer division since 2016 and was widely seen as a likely successor to Bezos. Wilke has been with the company since 1999.

He will be replaced in his role by Dave Clark, Amazon's current senior vice president for worldwide operations, who joined Amazon in 1999.

Wilke's surprise departure comes as demand for Amazon (AMZN) deliveries has surged during the pandemic. Last month, Amazon's revenue during the three months ended in June blew away Wall Street projections.

The online retail giant reported $88.9 billion in revenue, up 40% from the same period a year earlier. Net income doubled during the quarter to $5.2 billion, despite the company's more-than $4 billion investment in managing the pandemic in the period.

Amazon is also facing scrutiny from lawmakers over its competitive tactics.

Bezos last month testified on Capitol Hill alongside the CEOs of Apple (AAPL), Facebook (FB) and Google (GOOG)as part of a congressional antitrust probe. During the hearing, Bezos acknowledged that Amazon may have improperly used third-party seller data to inform its own product decisions — a key concern over the company's approach to competition.