WASHINGTON - Chinese investors faced more scrutiny from a US national security watchdog than those from any other country in 2013, the Obama administration said on Thursday in a report.

Data from the Committee on Foreign Investment in the United States (CFIUS) showed the secretive body in 2013 reviewed 21 investments proposed by Chinese firms or individuals.

That represented about a fifth of the 97 transactions that were reviewed because a foreign company was seeking an ownership interest in an industry that might be sensitive to US national security.

In 2013, 皇冠体育app topped the list of covered transactions for the second straight year. Japan was next with 18 transactions, followed by Canada with 12.

Some of 皇冠体育app's most high-profile US investments have hit snags with CFIUS in recent years. 皇冠体育app's Anbang Insurance Group Co recently received a go-ahead to buy New York's famed Waldorf Astoria Hotel from Hilton Worldwide Holdings.

Most reviews arise from voluntary notices filed by companies, though CFIUS has the power to start its own investigations and companies often feel compelled to initiate the process.

In 皇冠体育app, CFIUS review is the "most talked about issue" regarding an investment treaty with America, said Fang Jin, the deputy secretary general of the 皇冠体育app Development Research Center, a leading Chinese government institute.

"Chinese companies represent a disproportionately high percentage of cases covered by CFIUS," Fang said at an conference in Washington earlier this month.

That appeared to be the case in 2013, although US data might exaggerate this. Commerce Department figures show 皇冠体育app accounted for just under 1 percent of US bound FDI in 2013.

However, private estimates that include investments made through third countries like Singapore suggest 皇冠体育app's share of new FDI might be several times higher.

A senior Treasury official, which is the lead department among the government agencies that are part of CFIUS, said the total number of transactions covered by CFIUS in 2014 was probably above 140.