JK Rowling offers to pay annual salary of Tweeter who used Civil Service account to accuse Boris Johnson of being an 'arrogant, offensive truth-twister'

• Tweet slamming the Tories was sent out during last night's press briefing 
• Post surfaced as Boris Johnson defended his top aide Dominic Cummings 
• Cummings was facing fury over allegedly breaking lockdown three times 
• Mystery person tweeted from the Civil Service Twitter account 
• Do YOU know who Civil Service tweeter is? Email s.murphy-bates@mailonline.co.uk 

Harry Potter author JK Rowling has offered to pay the annual salary of the person who tweeted on the Civil Service Twitter account accusing Boris Johnson of being an 'arrogant, offensive truth-twister'.

The tweet was posted the press conference during which the Prime Minister defended his chief adviser Dominic Cummings.

A tweet from the account read: 'Arrogant and offensive. Can you imagine having to work with these truth-twisters?' The statement remained live for nine minutes, during which time it received 30,000 retweets.

It remains unclear whether the account had been hacked, or whether the message was posted in error, or by a disgruntled member of staff. A spokesman for the Government confirmed that an investigation was under way.

But Ms Rowling wrote on Twitter: 'When you find out who it was, let us know. I want to give them a year's salary.'

She added: 'I can't remember a clearer demonstration of contempt for the people from a sitting Prime Minister. Johnson might as well have shambled into shot, given us all the finger and walked off again.'

Celebrities including Gary Lineker, the Match of the Day presenter have also posted in support of the person behind the tweet.

Guardian writer Owen Jones mocked Boris Johnson's claim that Cummings was simply following his instincts, saying the civil servant was doing the same. Comedy writer James Felton and actor Ralf Little tweeted in solidarity with the post. 

Mr Johnson defended Mr Cummings for travelling to Durham for childcare during the lockdown when his wife developed symptoms of coronavirus.

Ms Rowling, who is married to a doctor and suffered coronavirus symptoms, also previously angrily reacted to tweets from Cabinet Ministers supporting Mr Cummings.

When Chancellor Rishi Sunak said on Twitter: 'Taking care of your wife and young child is justifiable and reasonable, trying to score political points over it isn't,' the writer hit back.

'People have missed funerals of loved ones because of lockdown. Many have had to look after their own young children while ill. One of the architects of the rules keeping those people housebound drove across the UK, knowing he had the virus. Indefensible hypocrisy and selfishness,' Ms Rowling tweeted.

And Ms Rowling was equally furious when when Foreign Secretary Dominic Raab wrote that 'It's reasonable and fair to ask for an explanation on this. And it has been provided: two parents with Coronavirus, were anxiously taking care of their young child. Those now seeking to politicise it should take a long hard look in the mirror.'

Ms Rowling said: 'So those who make the rules get to break the rules? Your government explicitly told us not to visit elderly relatives. Look in your own bloody mirror.'

She later added: 'Update to lockdown rules: parents who think they might have coronavirus should drive straight to relatives' houses halfway across the UK or risk their children being taken into care.

'The lockdown measures were presented as a great national collective endeavour and they were accepted by the public on those terms too. Now it seems they were optional so long as, that is, you have the correct connections.'

And when Culture Secretary Oliver Dowden tweeted: 'Dom Cummings followed the guidelines and looked after his family,' Ms Rowling retorted: 'I know ending stories and this ain't it, chief.'

Earlier this month Ms Rowling announced that she is making a £1m donation to help homeless people and those affected by domestic abuse during the coronavirus pandemic.

The writer said she was 'torn between pride and anxiety' for frontline health and care workers. Ms Rowling has been married to Dr Neil Murray, a Scottish doctor, since 2001.

Ms Rowling said last month that she has 'fully recovered' after suffering 'all symptoms' of coronavirus.

The Edinburgh-based author, 54, said she had not been tested for COVID-19. She said she had instead used a breathing technique to get air into the base of her lungs and shared a video of a doctor advising people how to do it.

Ms Rowling is now said to be worth £765m. But she has also donated much of her wealth to charity, with some reports saying that she has given away more than $100 million to philanthropic causes.