The number of pirate DVDs made in the UK rose 133% in the first half of 2005, anti-piracy campaigners have said.
Jonathan Ross has fronted an anti-piracy campaign
The Federation Against Copyright Theft (Fact) seized 386,569 UK-made fake DVDs from January to June, as UK seizures of pirate DVDs from abroad fell.
UK criminals earn £600m per year from pirate DVDs, an anti-piracy campaign fronted by TV host Jonathan Ross said.
Pirate DVDs, CDs and equipment worth £400,000 were seized from a factory in Southall, west London, last weekend.
Statistics released by Fact showed an increase in the number of pirate DVD produced within the UK, compared to the first six months of 2004.
In contrast, the number of imported pirate DVDs seized in the UK fell by 123,719 last year to 661,581.
Jim Angell, Fact's director of operations, said: "This shows that criminals are attempting to stay ahead of the game by trying to evade detection at British ports."
The Industry Trust for Intellectual Property Awareness said serious criminals were behind the "seemingly innocuous" trade in illegal DVDs.
An anti-piracy campaign fronted by BBC television and radio presenter Ross claims that by buying counterfeit DVDs from car boot sales and street traders, viewers were feeding crime in their local communities.
"Saying yes to a pirate DVD is also saying yes to crime on your streets," Ross said.
"There is a price to pay for pirate DVDs and it's much higher than most people think."
The anti-piracy body estimated that 30% of sales of major new DVD releases were lost because of fake discs.
Last week £400,000 of counterfeit stock and equipment was seized in Southall as police shut down what they described as the largest counterfeit CD and DVD factory ever uncovered in western Europe.
Aziz Ul Haq, 48, Ahmed Siddique, 22, and Nadeem Khan, 23, of Park Avenue in Southall, were remanded in custody, facing 11 charges of possession of fake DVDs.
More than 50,000 CDs and DVDs were seized from the factory, with a street value of around £1m.
They included copies of blockbusters War of the Worlds and Mr and Mrs Smith, and Bollywood hits such as Salaam Namaste, Mere Jeeran Saathti and My Wife's Murder.