Firefighters joined their colleagues from the police at HMP Ranby where a disturbance involving prisoners is ongoing.
Shortly after 7.30pm around 15 firefighters arrived outside the prison and began putting on their full kit before walking in through the main gate.
Officers carrying shields and other equipment were also seen going into the prison earlier.
More top news
A senior employee at the organisation reportedly derided the three-year-old royal for being 'royal, rich' and "advantaged'.
The company plead guilty to two counts of breaching the Health and Safety at Work Act after the grisly accidents.
In the run-up to the Rio Olympic Games, ITV News speaks to four Olympic hopefuls in Team GB. Today we profile gymnast Claudia Fragapane.