An alleged neo-Nazi record producer and his son and daughter are standing trial accused of stirring up racial hatred - as a court heard the father gave names of members of his far-right group to police during meetings with Special Branch officers.
Robert Talland, 54, from Waltham Abbey in Essex - known as "Ginger Rob" - is accused of encouraging terrorism through records released on his label, Rampage Productions.
His two children, Stephen, 34, and Rosie, 32, who played in a band called Embers of an Empire, are accused of stirring up racial hatred through concert performances and an album called Phoenix Rising.
Robert Talland allegedly made "considerable sums of money" through his label, merchandise and putting on gigs across Europe for a network of far-right bands called Blood and Honour.
One of the largest events celebrated a musician called Ian Stuart Donaldson, who founded Blood and Honour and died in a car crash in September 1993.
Martin Hall, a retired Special Branch officer with Northamptonshire Police, described four meetings with Talland between 6 September 2011 and 5 August 2014 in order to obtain information to "assist local policing" in managing the gig.
At the first meeting, held at a motorway service station on the M1, Talland told him about a "splinter group" called the Racial Volunteer Force, Mr Hall said.
But when asked about that year's memorial concert, he was "very vague and wouldn't give specifics about numbers or venues", Mr Hall added.
At a second hour-long meeting on the evening of 29 August 2013, the court heard Talland told Mr Hall that bands would be travelling from Italy and Germany and there would be British bands including Whitelaw, Nemesis, Brutal Attack, and Legion of St George.
Alistair Richardson, prosecuting, said Talland was asked if Blood and Honour had any members attending from Northamptonshire, and he gave three names.
At a follow-up meeting on 8 September, held at a supermarket in Northampton, Mr Hall was told the event would start on 20 September at the Red Lion truck stop, near junction 16 of the M1 in Northamptonshire, the court heard.
The last meeting was held on 5 August 2014 at the same supermarket and Mr Hall was told that year's gig would take place between 19-21 September, although a venue had not yet been agreed, the jury was told.
Talland was asked if anyone from Northamptonshire would attend and "gave his own and three other names", Mr Hall said.
Mark Gadsden, defending, claimed there had been other meetings and accused Mr Hall of "downplaying the usefulness of Mr Talland".
The barrister said that Mr Hall had asked Talland to let him know if there was "anyone behaving unpredictably or (who) might be a bit of a loose cannon" and Talland had told him about a drug user expelled from the group.
Talland had also told Mr Hall about members in the Northampton area and that members would stay at a local bed and breakfast and Premier Inn, opposite the Red Lion truck stop, because they were "getting older and camping out is not as comfortable as it used to be", the court heard.
"There was no secrecy was there?" Mr Gadsen asked. "There was no, 'I won't let you know this because you might go out and arrest him or investigate him?' He was open and honest."
Mr Gadsden said Talland and Mr Hall got on "pretty well" and the officer "only had to ask and he gave it to you".
Mr Hall told the court the contact had ended in 2014 but messages and emails suggested the pair had met again in 2017.
All the defendants deny charges of stirring up racial hatred and Robert Talland also denies encouraging terrorism.
The trial, at Woolwich Crown Court, continues.