The leader of the British National Party has been arrested as part of a police inquiry following the screening of a BBC documentary.
A party spokesman said Nick Griffin was arrested on Tuesday morning on suspicion of incitement to racial hatred.
West Yorkshire police confirmed they had arrested a 45-year-old man from outside their area.
BNP founding chairman John Tyndall was arrested on Sunday on the same charge.
In July, the BBC documentary Secret Agent featured covertly-filmed footage of BNP activists.
Mr Griffin is the twelfth man to be arrested following the documentary.
Nine men from West Yorkshire and another man from Leicester have been arrested and freed on bail.
Seven of the men had been held variously in connection with suspected racially aggravated public order offences, conspiracy to commit criminal damage and possession of a firearm.
Two men, both from Keighley, were arrested in September on suspicion of conspiracy to commit criminal damage.
A 24-year-old man from Leicester was detained on Monday on suspicion of incitement to racial hatred.
A BNP spokesperson said Mr Tyndall, from Brighton, was arrested following a speech he made in Burnley, Lancashire, and was released on police bail.