Chinese authorities launched their first ever probe into alleged price-fixing of DRAM chips against Samsung Electronics, SK Hynix and Micron Technology, Reuters reported.

The three companies, the largest suppliers of DRAM chips in the world, confirmed officials from China’s State Administration for Market Regulation had visited their offices, the news agency stated. DRAM prices have risen sharply over the past two years, it added.

Samsung and SK Hynix are based in South Korea, while Micron Technology is headquartered in the US.

Bernstein analyst Mark Newman told The Wall Street Journal China might be using high DRAM prices to launch an investigation that could pressure chipmakers to share technology.

The investigation also follows increasing trade tensions between China and the US.

After the US imposed sanctions on China-based ZTE, Chinese officials said the ban highlights the need for the country to reduce its reliance on non-domestic technologies, particularly those from the US. Senior officials reportedly met in late April to discuss accelerating the country’s already aggressive plans to become self-sufficient in core technologies such as chips.

In addition, Chinese antitrust regulators have dragged their feet on approving Qualcomm’s proposed acquisition of NXP Semiconductors: the only regulators yet to approve the deal.