The 41-year-old senior soldier is accused of national security offences and is being questioned in London.
A ten-year strategy to raise £500m from the Duchy of Cornwall will see farms sold off across England.
The man, charged with spying for China, said he was "unprofessional" to send "gossiping" texts to a friend.
Lilly Creightmore, who has alleged Walliams "groomed" her as a teenager, has told BBC Newsnight that she was "angry" at his behaviour.
The author and comedian recently lost a court battle trying to block publication of the allegations.
Jeri Cormack, 28, looks after three historic lighthouses in Caithness on the edge of the British mainland.
