Chinese telecoms giant Huawei has hit back at US politicians who labelled it a security threat.
A senior executive told the BBC that Huawei should not be treated unfairly just because it was Chinese.
In October the United States House Intelligence Committee warned US companies against dealing with Huawei and another Chinese telecoms firm, ZTE.
A report by the committee asked whether the firms were too close to China's Communist Party and its military.
It also suggested their products and services could pose a long-term security threat to the United States.
But a Huawei board member, Chen Li Fang, told the BBC the company, now number two in the telecoms equipment industry, was focussed on delivering secure products.
"We totally understand concerns about cybersecurity," she said. "But if any congressman or woman raises concerns or fears because a company originates in a particular country, I don't think that would be fair."
Huawei, founded in 1987 by a former officer in China's People's Liberation Army, has grown rapidly and now employs more than 140,000 people around the world.
Its main focus has been building a powerful position in the telecoms infrastructure industry, making equipment for the rollout of 3G and 4G networks. But it is also expanding into other areas, from mobile broadband dongles to smartphones and tablet computers.
Chen Li Fang, a Huawei veteran known at the company as Madam Chen, said the company was determined to make itself better known, and saw itself as a model for other Chinese companies.
"Huawei might not be famous now," she said. "But three billion people are using our products either directly or indirectly."
While the company has met with suspicion in the United States, it has been welcomed in the UK.
In September Huawei's founder, Ren Zhengfei, visited Downing Street after announcing a £1.3bn investment in the firm's growing UK operation. The Prime Minister David Cameron said the investment showed the UK was "open for business".
However the BBC's security correspondent Gordon Corera says the UK's Intelligence and Security Committee, chaired by former Foreign Secretary Sir Malcolm Rifkind, is currently looking at Huawei to try and understand what the risks might be and assess what measures have been taken to deal with them.
"The UK's relationship with Huawei has been a sensitive issue for a number of years," he said.
"But British officials argue they have found a way to work with Huawei and establish a working level of trust."
The Chinese firm has been working with BT for more than a decade on the rollout of its broadband network.
In China the accusations against Huawei have been met with anger, and suggestions that the US is simply trying to protect its own position in the telecoms industry against competition.
Qu Jian, of the China Development Institute, a think tank based in Shenzhen, said it fitted into a long-term pattern of protectionism.
"Since World War II, we've seen the US treating foreign companies just like this," he said.
"Every 20 years there's a big movement of manufacturing. In the 1960s it was to Japan, in the 1980s to South East Asia, and for the last 10 years to China. And every time there's a dispute between the new manufacturing base and the United States."
But with China suspected of being the place where many of the world's cyber-attacks originate, suspicions linger about its most powerful telecoms business - and not just in the United States. Australia barred Huawei from a role in building its national broadband network, citing the importance of maintaining the security of its vital infrastructure.
'Lack of trust'
The company's executives hope that eventually they will be able to overcome these suspicions.
Ron Raffensperger, an American who worked across the global telecoms industry for 30 years before taking up a senior engineering role at Huawei's Shenzhen headquarters, said: "It's all based on misunderstandings and a lack of trust.
"There's a reason so many of the companies around the world use us, and it's not because we're cheap, it's because we do really good stuff."
But, with the report from Sir Malcom Rifkind's committee expected before Christmas, Huawei can expect its policies and practices to be under the spotlight for some time to come.