It has been more than three weeks since Prince Alwaleed bin Talal, the most prominent investor in Saudi Arabia, was arrested on a Saturday night as part of the sweeping detention of several dozen elites. Since then, he has been holed up inside the Saudi version of prison for the ultrawealthy: the Ritz Carlton hotel in Riyadh, about a 10-minute drive from the prince’s home.

He hasn’t been heard from, nor have any charges against him been made public.

Because he was the longtime public face of finance for Saudi Arabia, Prince Alwaleed’s arrest — and the lack of transparency around what has happened to him — is causing increasing consternation among his various business partners and in much of the Western business community.

His arrest has also created a sense of uncertainty among investors about whether to do business with Saudi Arabia and, by extension, could affect some of its partners, like Masayoshi Son’s $100 billion SoftBank fund, in which the kingdom holds a 45 percent stake. It could also affect the highly anticipated public offering of the state-owned oil company, Aramco, planned for next year.

“I’m surprised that he got swept up in this, because he had always been such a positive figure both in reality and symbolically for Saudi progressivism — for participating in the modern world, in modern finance,” said Richard Parsons, a former chief executive of Time Warner and former chairman of Citigroup, in which the prince had also been a large investor.