Paddy Tipping, Labour's police commissioner, has said a 'no deal' Brexit could mean Nottinghamshire Police are "unable to exchange data" with other European crime agencies and lose the ability to execute European arrest warrants.
He has called for a "confirmatory vote" on Brexit to ensure the economy is not left "worse off", outlining the potential challenge a no-deal could have to Nottinghamshire Police.
He said: "Leaving the EU will unavoidably have a negative impact on Nottinghamshire Police and our ability to tackle crime in our community, as well as across the UK.
"Knife crime, and other serious crime, is on the rise nationally, including here in Nottinghamshire. We are reacting very strongly to this.
"Sufficient funding is absolutely critical for effectively tackling the rise in serious crime. As police and crime commissioner, I face a difficult and ongoing challenge in ensuring that Nottinghamshire Police is adequately resourced to meet local demands.
"All analysis clearly indicates that the Brexit that is being pursued by the Tories would leave the UK economy worse off. If the chancellor has less money to distribute and our central funding is further squeezed, that resourcing task is only going to get harder.
"Our operational capacity would be reduced, crime will rise and our community will suffer.
Like any other police force in the UK, Nottinghamshire Police are currently able to draw on a range of EU-wide systems for tackling cross-border crime.
Mr Tipping added that if the UK crashes out of the EU without a deal, Nottinghamshire Police would lose the ability to exchange data such as criminal records, DNA and fingerprints with other European crime agencies.
He said: "In a no-deal crash-out scenario we would lose access to those systems, such as SIS-2 and the European arrest warrant.
"We would lose our ability to exchange data such as criminal records, alerts on wanted individuals, DNA, fingerprints and airline passenger information with other European crime fighting agencies.
"The European arrest warrant, for example, has been a great help here in the UK in operations against serious organised crime.
"It has been successfully used, for example, to take action against people traffickers who have smuggled vulnerable adults and children to the UK from eastern Europe.
"We have a great EU deal already, our existing membership. To keep our communities safe we need to remain. That's why I back a confirmatory vote."