A former parliamentary researcher from Scotland arrested on suspicion of spying for China has insisted he is "completely innocent".

The man said he had spent his career highlighting the "challenge and threats presented by the Chinese Communist Party".

The arrest under the Official Secrets Act led to the Prime Minister confronting Chinese premier Li Qiang at the G20 summit in India on Sunday over "unacceptable" interference in democracy.

In a statement released through his lawyers, the researcher - who has not been officially named by police - said: "I feel forced to respond to the media accusations that I am a 'Chinese spy'.

READ MORE: China spy Edinburgh: Sunak faces pressure over alleged security breach

"It is wrong that I should be obliged to make any form of public comment on the misreporting that has taken place.

"However, given what has been reported, it is vital that it is known that I am completely innocent.

"I have spent my career to date trying to educate others about the challenge and threats presented by the Chinese Communist Party.

"To do what has been claimed against me in extravagant news reporting would be against everything I stand for."

The Herald:

Chinese Premier Li Qiang takes the oath of office after he was re-elected as Premier during a plenary meeting of China's National People's Congress (NPC) at the Great Hall of the People in Beijing, Sunday, March 18, 2018. (AP Photo/Mark Schiefelbein).

The Scot, who is in his late twenties and went to George Watson's College in Edinburgh, was arrested along with another man by officers on March 13 on suspicion of spying for Beijing, it was revealed by the Sunday Times.

READ MORE: Spy row: Scot arrested on suspicion of spying for China

Officers from the Metropolitan Police's Counter Terrorism Command, which oversees espionage-related offences, are investigating.

The Scot was arrested in Edinburgh, while the other man in his 30s, was detained in Oxfordshire, Scotland Yard said.

Both were held at a south London police station before being bailed until early October.

The arrests were only revealed at the weekend and the researcher at the centre of the row had links with senior Tories including security minister Tom Tugendhat and Foreign Affairs Committee chairwoman Alicia Kearns.

Mr Tugendhat is said not to have had any contact with the researcher since before he became security minister in September last year.

Ms Kearns declined to comment, adding: "While I recognise the public interest, we all have a duty to ensure any work of the authorities is not jeopardised."

Commons Speaker Sir Lindsay Hoyle will address MPs about the situation at the start of Monday's business in the chamber.

The allegations have led to increased pressure from China "hawks" on the Tory benches for the Prime Minister to toughen his stance towards Beijing.

During the Tory leadership contest last year, Mr Sunak described China as the "biggest long-term threat to Britain" but official language used since he took office has been softer, with the integrated review of foreign and defence policy calling it an "epoch-defining challenge".

Business Secretary Kemi Badenoch suggested that designating China a threat would "escalate things" with Beijing.

She told BBC Radio 4's Today: "China is the second largest economy in the world, it's heavily integrated in our economy as it is with many of our allies... We're taking the same approach that those countries are taking."

Ms Badenoch said the UK was taking certain measures including making sure it has proper investment screening.

"We are taking action, what we're not doing is giving endless running commentary on that because that would actually be more helpful to China than it would be to our security services," she said.

Sir Iain Duncan Smith, the former party leader who has been sanctioned by China, was among Tories pressing the Prime Minister to strengthen his language towards Beijing.

He hit out at the "weak" position of not labelling China a threat, telling the PA news agency: "The result is that China is penetrating all our institutions from universities to Parliament. Time to speak through strength not weakness."

Tory backbencher and Home Affairs Select Committee member Tim Loughton, who has also been sanctioned by Beijing, told Times Radio: "It really is not remotely appropriate that those of us most in the firing line, being sanctioned by China under threat by China, have not been given some briefing about exactly what's happened."
China hit out at the arrests and claimed the situation was a "political farce".

A spokesman for China's embassy in London said: "The claim that China is suspected of 'stealing British intelligence' is completely fabricated and nothing but malicious slander.

"We firmly oppose it and urge relevant parties in the UK to stop their anti-China political manipulation and stop putting on such self-staged political farce."

Former head of MI6 Sir Alex Younger said co-operation with China is necessary but "just being nice to them doesn't get you very far".

He told Today: "China is a fact, it's a huge country, we've got to find ways of engaging with it, and find ways of co-operating with it in important areas like climate change, and sometimes we have to be absolutely prepared to confront it when we believe that our security interests are threatened."