Evidence sessions in an inquiry into the attacks that concluded last month revealed Nottinghamshire Police had an active, outstanding warrant for Calocane for a vicious assault on a police officer dating back months before the attacks.

In addition, mental health services revealed Calocane was discharged because ‘they couldn't find him' despite warnings he posed a danger to the public.

A spokesperson for Nottinghamshire Healthcare NHS Foundation Trust said: ‘Northumbria Police, acting on behalf of Nottinghamshire Police, have begun an investigation into matters relating to the care and treatment of Valdo Calocane.

‘We know how important the independent inquiry and police investigation are for the affected families, the survivors and our local communities.

‘We will, of course, be co-operating fully with Northumbria Police, as we have with the Statutory Inquiry into these matters which is being chaired by Her Honour Deborah Taylor, and which will hear final submissions from all the parties involved later this year.'

A spokesperson for Northumbria Police said: ‘Our thoughts are very much with the victims, their families and all those impacted by the tragic events in Nottingham in June 2023.

‘We can confirm we are subsequently carrying out an investigation on behalf of Nottinghamshire Police.

‘We are in contact with the victims' families and survivors and are committed to supporting them throughout this process.

‘It would not be appropriate for us to comment any further.'