The father of a man whose grave was damaged says he was sickened by the attack.
Dad Paul Joy lost his son Andrew, aged 38, in March this year.
Andrew had severe learning and physical disabilities and had not been expected to live beyond a young age.
Mr Joy said he was sickened when he discovered Andrew’s grave at Burton Latimer Cemetery had been violently attacked on either July 15 or 16.
The attack happened shortly after he had a confrontation with a man walking three dogs. He asked the man to keep the dogs on a lead.
Mr Joy said: “My wife and I were watering some flowers at Andrew’s grave, because of the hot weather, on the evening of Monday, July 15.
“I saw a man walk through the cemetery with a young blonde girl, aged about four, and three terrier-type dogs which were running all over the place.
“I thought it was a bit unusual and I called out to him that the dogs should be on a lead. He didn’t say anything but he made a gesture towards me and carried on walking away.”
Mr Joy said he and his wife left the grave soon afterwards and drove home.
He added: “The next morning I was walking my own dog near the cemetery when a friend of mine came running over and warned me that Andrew’s grave had been damaged – he didn’t want me to come across it on my own so he walked with me back into the cemetery.”
Mr Joy discovered that a wooden cross, used as a temporary grave marker, was missing and has never been found.
Planters had also been kicked over and some metal pegs which were in the ground had been stamped on and bent.
Mr Joy said: “I don’t think whoever did this targeted Andrew’s grave in particular, it was just mindless. It was very upsetting. We’ve repaired the damage and replaced the wooden cross now.
“A lot of force was used to stamp on the pegs as they were completely bent.”
Northamptonshire Police say they would like to speak to the man seen walking the dogs through the cemetery prior to the incident. Anyone with information should phone 101.
Alternatively, people can call Crimestoppers on 0800 555111.
A policee spokesman said the dog walker was a white man, aged about 30 years old, with short, dark-coloured hair which may be thinning.
The spokesman said: “He was about 6ft and had three small terrier type dogs with him. One was white, another black and the third was a light colour.”