Coroners should be free to act "without attack or intimidation", the chief coroner's office said after five people were arrested for storming a west London coroner's court.
The yellow vest protesters forced entry to senior coroner Chinyere Inyama's office in Fulham, west London, on Thursday, live-streaming the event.
In a video viewed almost 20,000 times by Thursday evening, the coroner remains silent as he is criticised by the group.
At one point during the footage, which lasts just over half an hour, an apparent struggle erupts between a protester and a member of court staff.
A spokesman for the Chief Coroner, Judge Mark Lucraft, said: "The Chief Coroner was very troubled to hear of the attack on the coroner's court in west London.
"Coroners are judicial office holders carrying out important public duties and they, along with their officers and other staff, must be allowed to deal with cases and make independent judicial decisions without attack or intimidation from anyone - whatever their interests or motivations."
The protest related to the deaths of three teenage boys who were hit by a car as they walked to a 16th birthday party.
Jaynesh Chudasama was jailed last year after pleading guilty to causing the deaths of semi-professional footballer Harry Rice, 17, apprentice electrician George Wilkinson, 16, and labourer Josh McGuinness, 16, by dangerous driving.
The car hire worker was more than two-and-a-half times the legal limit for alcohol and doing 71mph on a 60mph road in Hayes, west London, when he ploughed into the teenagers.
His 13-year prison term was cut to 10-and-a-half years by three judges at the Court of Appeal in London.
Josh's mother, Tracy Blackwell, was one of the group filmed at West London Coroner's Court on Thursday, demanding an inquest and criticising the way Mr Inyama had dealt with the case.
In the video footage posted online, the group chant "Josh, George, Harry" after police officers arrive, before eventually leaving Mr Inyama's office.
The Metropolitan Police said they had arrested four men and one woman. No arrests were made on camera.
It comes after protesters wearing yellow vests tried to storm the Attorney General's office in a similar incident last month.