A 55-year-old man has been arrested on suspicion of making online threats to Gina Miller, the businesswoman who won an appeal against the government triggering Article 50 without parliamentary approval.
The suspect has been arrested on suspicion of racially-aggravated malicious communications after police said they were made aware of threats made against a woman on 3 November, the date High Court ruled that MPs must be able to vote before Theresa May triggers formal proceedings to leave the EU.
He was taken into custody at a Wiltshire police station, where he was later released on bail. As part of the same investigation, a 'cease and desist' notice was also issued to a 38-year-old man from Fife, Scotland on 3 December.
The government launched an appeal against the High Court decision, with proceedings currently taking place at the Supreme Court.
At the start of the hearing, Lord Neuberger, President of the Supreme Court, urged that names or other details such as addresses of the certain former claimants in these proceedings not be published as various individuals has received "threats of serious violence and unpleasant abuse in emails and other electronic communications".
He added: "Threatening and abusing people because they are exercising their fundamental right to go to court undermines the rule of law. Anyone who communicates such threats or abuse should be aware that there are legal powers designed to ensure that access to the courts is available to everyone."
A Metropolitan Police spokesperson said: "Officers from the Met's Falcon Unit have arrested a man on suspicion of racially aggravated malicious communications. An investigation was launched by Falcon detectives after police were made aware of threats made online against a 51-year-old woman from 3 November onward.
"The 55-year-old man was arrested on Monday, 5 December at an address in Swindon. He was taken into custody at a Wiltshire police station, where he was later released on bail pending consideration by the Crown Prosecution Service.
"As part of the same investigation, officers also issued a 'cease and desist' notice on 3 December to a 38-year-old man from Fife, Scotland."