Updated The BNP's "membership list" has been leaked for the second time in a year, it's claimed today.
Wikileaks has posted an Excel spreadsheet containing just over 16,000 identities, including many addresses and phone numbers.
The list is dated up to April 15 this year.
The BNP said it had not yet confirmed whether the list was genuine, but insisted it had been released this week to overshadow leader Nick Griffin's imminent appearance on Question Time.
Both Wikileaks and the BNP suggested some of the names listed may not be members.
The alleged data breach follows a similar incident in November last year, when a list of more than 10,000 members was posted to the internet. Griffin made a complaint to the police and in September a disgruntled party insider was fined £200 for leaking the data.
Separately today, a coalition of senior military figures called on the BNP to stop associating itself with the British forces.
"The values of these extremists — many of whom are essentially racist — are fundamentally at odds with the values of the modern British military, such as tolerance and fairness," the chiefs, including General Sir Mike Jackson and General Sir Richard Dannatt, said in an open letter. ®
The BNP claims the list published today contains no new data and branded it a "malicious forgery".
"We have had a chance to examine the list in detail and can unequivocally say that it is not a genuine BNP list," Nick Griffin said.
"The list includes thousands of people with renewal and membership numbers next to their names which are totally false and made up."
"We have no idea from where this information has been drawn. Some of it looks like random items drawn from a telephone book."
Wikileaks said: "The lists have been verified to be accurate in all cases examined by Wikileaks."