The Czech National Cyber and Information Security Agency (NCISA) has warned the country’s network operators not to use any software or hardware made by Chinese telecom equipment suppliers Huawei and ZTE.

According to a statement issued by the Czech cyber watchdog on December 17, there is a security threat associated with these companies’ products.

“China’s laws… require private companies residing in China to cooperate with intelligence services, therefore introducing them into the key state systems might present a threat,” Dusan Navratil, director of the Czech National Cyber and Information Security Agency (NCISA), said in a statement.

As reported by the Reuters news agency, Huawei, the world’s biggest producer of telecoms equipment, faces intense scrutiny in the West over its ties to the Chinese government and concerns its equipment could be used by Beijing for spying. The company has repeatedly denied the allegations.

In response to NCISA’s warning, a Huawei spokesman said: “We categorically deny any suggestion that we pose a threat to national security. We call for NCISA to provide evidence instead of tarnishing Huawei’s reputation without any proof.”

“There are no laws or regulations in China to compel Huawei, or any other company, to install ‘mandatory back doors’,” he added, a reference to US warnings that Huawei’s network gear could contain ‘back doors’ that would allow Chinese spies to hack into critical network infrastructure.

“Huawei has never received any such request from any government and we would never agree to it,” the spokesman said.

Meanwhile, the arrest of a top Huawei executive in Vancouver, Canada, at the request of US authorities on December 1 has sparked a diplomatic dispute. According to Reuters, Meng Wanzhou, Huawei’s chief financial officer and the daughter of its founder, faces US allegations that she misled multinational banks about Iran-linked transactions, putting the banks at risk of violating US sanctions.