In a statement, police confirmed he had been warned about his conduct – but insisted the messages were not considered to be of a criminal nature.
A Northumbria Police spokesperson said: “We are aware of concerns relating to messages posted on social media and have spoken to the individual involved.
“Officers are satisfied that no criminal offences have been committed but have warned the individual about his behaviour. Anyone who has concerns can contact Northumbria Police by calling 101.”
Nimmo was jailed in February last year after admitting to nine charges relating to online threats at Newcastle Crown Court.
One of Nimmo's messages to Luciana Berger, the Labour politician and Britain’s youngest Jewish MP, he included a picture of a large knife. It was sent three weeks after the murder of MP Jo Cox.
He had sent two emails to Ms Berger in which he said she would "get it like Jo Cox" and "watch your back, Jewish scum".
Emails to an anti-hate crime group also included threats to blow up a mosque. He was jailed for 27 months.
Nimmo was previously jailed for eight weeks in 2014 for sending abusive messages on Twitter to feminist campaigner Caroline Criado-Perez and MP Stella Creasy.
