A blogger has claimed two police officers visited his home to advise that he take down tweets about UKIP policies.
Michael Abberton, a Green Party member, was told by the two Cambridgeshire Police officers he was being visited following a complaint from a UKIP member.
Police confirmed the visit but denied Abberton was advised to delete the Twitter posts.
The visit took place after he tweeted "fact checks" about UKIP policies in which he claimed to be verifying the truth behind claims made by the party.
He was told he had not committed any crimes and no police action was taken, but a complaint had been made by a UKIP member.
In his blog, Axe of Reason, Abberton said he was advised during then visit on Saturday to delete some of the Twitter posts.
He wrote: "They asked me to 'take it down' but I said I couldn't do that as it had already been retweeted and appropriated, copied, many times and I no longer had any control of it.
"I'd like to be absolutely clear – the police officers were extremely professional and polite and I couldn't fault their behaviour in any way.
"But it wasn't until after they left that I questioned why they had visited me in the first place.
"Why would a political party, so close to an election, seek to stop people finding out what their policies are or their past voting record?
"And is it not a matter for concern that a political party would seek to silence dissent and debate in such a manner?"
A Cambridgeshire Police spokesman said: "We were called with a complaint about a message on social media at about 12.40pm on Friday. Inquiries were made as to whether any offences had been committed under the Representation of the People Act but none were revealed and no further action was taken."
Last month, Press Gazette revealed two cases in which police have served journalists with "prevention of harassment" letters, which have been condemned by free speech activists.
Croydon Advertiser chief reporter Gareth Davies doorstepped a woman once and emailed her twice in order to put allegations to her before being visited by the Metropolitan Police.
Elsewhere, Florida-based UK journalist David Marchant revealed how he was given a harassment warning by the Met as a result of his investigation into an alleged £100m investment fraud. He insists that he has never contacted in any way the person he is alleged to have harassed.