A specialist anti-terror team has registered a jump in reports relating to extreme right-wing material online.
More than one in four referrals from the public about web content are now made over far-right concerns.
The national unit has instigated the removal of more than 304,000 online videos, web pages and posts since it was established in 2010.
Police said the vast majority of the content relates to Islamist extremism.
But the Counter-Terrorism Internet Referral Unit (CTIRU) has seen an increase during the past year in material related to extreme right-wing ideology.
Figures released by Scotland Yard show that of 1,849 public referrals to the CTIRU since March last year, 481, or 26%, related to extreme right-wing material.
Senior officers have warned that the threat from both Islamist and far-right terrorism is growing.
The CTIRU works with hundreds of organisations to remove content including propaganda and recruitment videos, images of executions and speeches calling for racial or religious violence.
Figures released today (April 6) show the unit has also provided key evidence and information in 226 counter-terror investigations since its launch.
The team's main function in previous years has been getting content taken down but officers have been able to shift their focus towards investigative work as tech providers step up their efforts to remove material automatically.