The 70-year-old, from Brighton, was arrested on Sunday night on suspicion of incitement to commit racial hatred.

In July, BBC documentary The Secret Agent featured covertly-filmed footage of BNP activists.

Five men from Bradford and four from Keighley in West Yorkshire have already been arrested and freed on police bail.

Seven of them had been held variously in connection with suspected racially aggravated public order offences, conspiracy to commit criminal damage and possession of a firearm.

The other two men, both from Keighley, were arrested in September on suspicion of conspiracy to commit criminal damage.