In the current scenario, the likelihood is high of steel being relabelled and exported to evade taxes, they say, adding that this poses a serious problem for the export sector as a whole.

In the first 10 months this year, Vietnam imported 4.64 million tons of steel from China worth $2.95 billion, according to latest statistics from Vietnam Customs.

China was by far the biggest exporter of steel to Vietnam, accounting for 37.9 percent of import volume in the period, followed by Japan with 14 percent.

Although the import volume and value of Chinese steel has dropped 12.8 percent in volume and 23 percent in value year-on-year, 4.46 million tons is still a large amount, and it is not clear whether Vietnam actually has enough demand to consume all this steel, according to economist Le Dang Doanh.

"4.46 million tons certainly exceeds what the domestic market can consume. If the U.S. finds out that some of it has been imported, relabelled as made-in-Vietnam goods, and exported, it could prove disastrous for our economy," he said.

Such a discovery could lead to the U.S. deciding to slap tariffs on steel exports from Vietnam, causing serious damage to the domestic steel industry, and could then look to do the same with Vietnam’s other export items, Doanh said.

In July, the U.S. slapped anti-dumping duties of up to 456 percent on some steel products imported from Vietnam, which it alleged were produced overseas.

According to the Vietnam Steel Association, Vietnam has turned into a "focal point" of anti-dumping lawsuits of many countries, especially after the start of the U.S.-Sino trade war, as companies looked to reroute Chinese steel through Vietnam.

So far, Vietnamese steel products have faced 35 out of 142 dumping investigations that other countries have initiated against Vietnam, according to a Ministry of Industry and Trade (MoIT) report released mid-October.