Graffiti demanding justice for a late fathers’ rights campaigner is being treated as criminal damage.
The message, scrawled on a fence next to the A602 in Stevenage, refers to a Haydn Burton – lately of the campaign group New Fathers 4 Justice.
Mr Burton was found dead in Winchester Prison last month.
A police spokesman said the graffiti was being treated as criminal damage and was the subject of an investigation.
A similar message was spotted on a banner alongside the A1(M) between Junction 7 and 8, but is not being probed by police.
Bobby Smith, a New Fathers 4 Justice activist who lives in the town, denied responsibility for the messages but said he supported them.
Mr Smith has confronted prominent politicians about fathers’ rights on a number of occasions and ran against David Cameron in his Witney constituency in the General Election.
He said: “I can’t take credit for the banners as they were done by another activist who lives in Stevenage. Of course, I fully support it and will most likely be doing similar soon.
“I met Haydn around a year ago at a protest in Central London. He had not seen his daughter for a long time.
“He asked my advice on how to protest, so I told him. He was a great protester and would campaign daily in his home town under the New Fathers 4 Justice banner while dressed as Superman.”
New Fathers 4 Justice confirmed local activists were visited by police on Wednesday afternoon.