A number of posts from a local Facebook page have been sent on to the authorities having been discovered before the Labour leader visited Whitby on December 1.
The posts included threats of violence and one even called for “the need for a sniper” before Mr Corbyn addressed a crowd with local candidate Hugo Fearnley on the town’s West Cliff as part of a campaign tour through Yorkshire.
Mr Fearnley addressed the comments during his speech to supporters and told the Local Democracy Reporting Service that the posts were not reflective of the people of the town.
He said: “There were some very concerning posts made on social media in the run-up to the visit.
Corbyn's eye-catching 'For the many, not the few' jacket made by Yorkshire tailor
“They went well beyond what is acceptable political disagreement and I could not let it go unmentioned when I spoke to those who came out.
“I do want to say that those posts do not reflect the people of Whitby. Whitby is a very welcoming place which has people coming to visit it from all over the world every day.”
As a party leader Mr Corbyn is subject to increased security protection during an election.
A Labour Party spokesman said it “would not comment on security arrangements” when asked if extra measures were put in place for the visit to Whitby due to the threats.
It is understood that local Labour members discovered the posts on the private Facebook group and passed them on to the party which then informed the police supervising the leader’s visit.
North Yorkshire Police has been approached for a comment.