The Democratic National Committee warned candidates running in the November midterms not to use devices manufactured by the Chinese electronics firms ZTE and Huawei, "even if the price is low or free," according to a CNN report.

The DNC was reportedly considering purchasing ZTE phone for its staffers when it issued its warning.

The warning comes amid renewed government scrutiny of consumer devices manufactured by Chinese companies.

The Democratic National Committee warned candidates running in the November midterms not to use devices manufactured by the Chinese electronics firms ZTE and Huawei, "even if the price is low or free," according to a CNN report published on Friday.

The DNC was reportedly considering purchasing ZTE phones for its staffers when it issued its warning, a senior Democratic source told CNN.

"It's very important that party and campaign workers not use ZTE or Huawei devices, even if the price is low or free," chief security officer Bob Lord reportedly wrote.

Lord also warned staffers not to use the Chinese-produced devices "anywhere within your staff - for personal or work-related use."

The warning comes amid government scrutiny of consumer devices manufactured by Chinese firms. Lawmakers like Sen. Marco Rubio of Florida, have criticized and pushed for economic penalties against ZTE and Huawei for their "extensive ties with the Chinese Communist Party," and their "track record of doing business with rogue regimes like North Korea and Iran."

"I personally don't believe we should be allowing any Chinese telecommunication company to do business in America because they use it as a tool of espionage," Rubio told Fox's Tucker Carlson on Friday night.

"In a country full of bad actors when it comes to hurting American jobs and threatening our national security, Huawei and ZTE are two of the absolute worst offenders," a group of bipartisan lawmakers said in a statement to block the US government from buying or leasing telecommunications equipment from the companies.

US intelligence agencies have also remained wary of the companies for possible cybersecurity risks. Agencies like the FBI, CIA, and NSA have expressed concern that companies like Huawei, which was founded by a former engineer in the Chinese People's Liberation Army, could be covert fronts for the Chinese government.

"It provides the capacity to maliciously modify or steal information," FBI Director Christopher Wray said to a Senate Intelligence Committee hearing in February. "And it provides the capacity to conduct undetected espionage."

Following the intelligence hearing, ZTE fought back against the claims and downplayed any security concerns.

"As a publicly traded company, we are committed to adhering to all applicable laws and regulations of the United States, work with carriers to pass strict testing protocols, and adhere to the highest business standards," a ZTE spokesperson said at the time.

The US imposed a supplier ban against ZTE in April, after it was caught violating US sanctions and was found to have shipped US technology to Iran and North Korea. While the ban was in effect and the fate of ZTE's US subsidiary was uncertain, the company is believed to have spent $1.4 million to lobby Washington through parties and donations, according to a New York Times report published on Wednesday.

The ban was lifted in July, after the company paid $1 billion as part of a settlement agreement.