Tim Cook, Chief Executive Officer of Apple Inc, was reportedly spotted in Beijing's business district on Monday, igniting speculation as to the reason behind his unexpected visit.

Apple CEO Tim Cook visits an Apple store in Xidan, Beijing on Friday in this photo uploaded by a Weibo blogger. [Photo/Weibo.com]

A photo of Cook walking around an Apple store in Xidan, one of most populated shopping districts in the capital, was first put online at noon by a blogger on Sina Weibo. The photo shows Cook wearing a dark-blue sweater and smiling as he listens to a staff member.

STwing, the blogger, claims Cook arrived at the store at 11am. The news has not been officially confirmed by Apple, but if true, this will be Cook's first visit to China, a move that was never made by Apple's founder and deceased CEO Steve Jobs.

The Xidan Joy City store is said to be the biggest Apple store in the world in terms of customer flow and sales volume, according to a report by Netease. Sales of the iPhone 4S soared to 380 million yuan on Jan 13, the first day of its launch in China.

The purpose of Tim Cook's appearance is still unclear. Insiders claim he has come for a meeting with Wang Xiaochu, chairman and chief executive officer of China Telecom Corp. Others speculate the visit is for the iPad trademark case against Proview Technology.

China Telecom, China's third-largest carrier, started to sell the iPhone 4S in China on Mar 9 following a contract signed with Apple in February, ending the iPhone combo monopoly with China Unicom.