The home secretary is to announce £9m of funding to help fight criminals who use the dark web.
The hidden layer of the internet, accessed through specialist software, allows users to be anonymous – attracting those who do not want to be traced, such as online drug dealers.
Amber Rudd says the money will "enhance" responses to the crime.
Funding will come from a previously announced £50m pot for the Home Office to improve the UK's cyber defences.
As well as drug dealers, the dark web is used by gun traffickers and people selling images of child abuse.
In a speech Ms Rudd will give to the CYBERUK security conference in Manchester later, she will describe the online space as a "dark and dangerous place where anonymity emboldens people to break the law in the most horrifying of ways".
She will say: "It is a platform of dangerous crimes and horrific abuse.
"[Specialist law enforcement forces] will use this money to help combat the criminals who continually exploit the anonymity of the dark web."
Exact measures are not being published for "operational reasons".
Another £5m of the £50m fund will go towards dedicated cyber crime units to fight online offenders at a local level.
Ms Rudd, whose father fell victim to cyber crime, will add: "Whilst criminals plot and hide behind their screens, their actions have real-life consequences for their victims.
"I know from personal experience the importance of supporting those who have been victimised through no fault of their own."
The home secretary will also encourage individuals and businesses to do what they can to protect themselves.
"In the same way that shops protect themselves from burglary with locks, alarms and security guards, I expect businesses to take equivalent precautions digitally," Ms Rudd will say.
"The world of cyber is fast-developing and we need a fast-developing response to match – one that recognises that it is the responsibility of everyone in the UK to fight the evolving threat."
Dark web crimes
In February, Kyle Enos, from Newport, was jailed for eight years for using the dark web to sell the high strength painkiller fentanyl.
And in the same month, paedophile Matthew Falder was jailed for 32 years for blackmailing victims and sharing abuse tips and images on the dark web.