A Shenzhen-based peer-to-peer (P2P) company has mysteriously vanished, leaving 600 investors unable to claim their 20 million yuan ($3.2 million) investment, the Guangzhou Daily newspaper reported Thursday.

The website of the Shenzhen-based P2P platform, wangwangdai.com.cn, cannot be opened, and no one has answered the customer service hotline since Tuesday afternoon, several investors were cited by the report as saying.

An unnamed investor said the company cannot be founded on the address the company claimed to be, National Business Daily newspaper reported Thursday.

Shenzhen Wangwangdai had won investors' trust by claiming it was insured by Shenzhen Nabaichuan Guaranty Ltd, but the platform is actually owned by Nabaichuan, the report said.

"It is very hard for investors to get their money back if management of P2P platforms flee," Ma Jun, chief analyst at Shanghai-based wangdaizhijia.com, a Web portal that tracks the industry, told the Global Times Thursday.

An investor surnamed Zhu said that Wangwangdai offered annual returns higher than 15 percent, according to the Guangzhou Daily report.

The normal return of P2P products range from 7 percent to 12 percent, Ma said, noting returns close to 20 percent usually indicate high risk.

Ma also suggested investors attach importance to the transparency of project information provided by P2P platforms. He said some P2P platforms, such as Beijing-based JimuBox, provide details about where investments go and how it will be used, but some other platforms only give vague information.

Dong Jun, CEO of JimuBox, told the Global Times that investors should also pay attention to P2P platforms' risk control mechanism, including whether the platforms conduct proper investigations on the projects and cooperate with qualified guaranty companies. This lessens the risks that projects might lose money and be unable to provide the promised returns to investors.

P2P lending platforms match people who want to invest money with individuals who are seeking loans, usually via online auctions. P2P lending has developed rapidly since the end of 2012, as part of the country's unregulated shadow banking system.

However, now there is no entry threshold for establishing P2P platforms, nor clear supervision rules for P2P platforms in China, Dong said.