Top company executives in China keep vanishing, and some never return to their posts.

This week, it was the CEO of the Hong Kong arm of one of China's largest brokerages who disappeared; a few months ago, the president of a giant bank.

Once they go missing, there's no telling when they'll resurface. In some cases, they show up again -- perhaps months later, and offering little explanation.

In others, state media report that the executive has been caught up in a government investigation, into insider dealing or bribery, for example. Few details are ever revealed.

Some of these cases appear to be linked to a campaign against corruption launched by President Xi Jinping in 2013. But lately, more seem to be tied to investigations related to China's summer stock crash. Officials have been casting around for people to blame for the wild market swings.

Either way, the bizarre case of China's missing executives has observers puzzled. Here's a look at four recent examples of unexplained absences:http://money.cnn.com/2015/11/27/inve...ng-executives/