In the months since the 22-year-old's death, Kevin's parents and fiancee have been expressing their sadness on the Gone Too Soon site.

More than 4,000 people have visited Kevin's page to share their memories of the Pennywell dad.

But now the family say it has been invaded by an anonymous web-user leaving messages of support for one of his alleged killers.

>> Leave your tributes for Kevin on our condolences page

Fiancee Adele, 27, who visits the site regularly to chat to Kevin, said: "We have been through enough already. Everybody is entitled to their opinion, but they must not have a heart to leave messages on a tribute site. It's disgusting."

The messages, posted by someone called "passer by", refer to Jordan Towers, 16, who was convicted of Kevin's murder alongside Dean Curtis, 19, and Tony Hawkes, 17, after a trial at Newcastle Crown Court last year.

Kevin was stabbed through the heart during a brutal attack just metres from his front door on Partick Road, Pennywell, Sunderland, last May.

But the web messages state Jordan's only involvement that night was throwing a rock in self defence and suggest that the minimum 13-year sentence given to the teenager is not justified.

Part of the anonymous message states: "If you new Jordan you would no that he is not capable of doing what he is accused of. He has been brought up with respect, maybe a few scrapes with the police for petty crime but what teenager doesn't.

"Jordan should of joined in that night at least he would be in prison for something he's done, he only was found guilty by association or joint enterprise."

Kevin's dad John Johnson, 57, said: "All three were in cahoots. They went out to cause havoc and they stuck together."

John, who is married to Katy, 57, says the public site has been a huge source of comfort to the family who have been able to share memories and read messages of support.

The taxi driver, who lives in Ryhope, said: "It's a tribute site to leave condolences not a site to slag each other off.

"A lot of people get comfort from these websites and now we've ended up getting heartache."

Gone Too Soon is one of the post popular condolence sites on the internet, posting tribute pages to thousands of people who have lost their lives. As well as a way of remembering Kevin, the website has also helped to gather momentum for the Enough is Enough campaign, which Mr Johnson launched to demand stiffer sentences for killers. He has collected 31,000 signatures so far.

John added: "We could take the site down, but then they would have won."

Since the messages started appearing on April 24, the family have contacted police and have tried to speak to the administrators of the site to see if something can be done about it.

Adele, who is mum to Kevin's 18 month son Chaise as well as Trey, eight, said: "They are ruining it for us. I go on there to speak to Kevin, it's like therapy for me."

* Last month the Echo reported on another grieving city family who had been left distraught after offensive messages were posted on the memorial website.

Helen Kerry, 19, of Edwin Street, Houghton, visited the site every day to leave messages to brother Paul who died in a car smash on the A690 Houghton Cut. But, during recent visits, she noticed postings that have been both offensive to those who have passed away and untrue. She even says tribute pages are being set up to non-existent people.

Those behind the site told the Echo they are working hard to stop this type of thing causing any further upset. Nicola Davis, from Gone Too Soon, said: "Gone Too Soon takes such abuse of the site very seriously, and we are able to identify the IP address of the perpetrators which we pass on to the police.

"In addition, to ensure that all our users can continue to enjoy this free service and benefit from this free service, we are launching a new version of the site.

"It will require all visitors who want to set up or leave a memorial message to create a secure profile which will require validation through use of a genuine email address and telephone number.

"We are confident these new security features will enhance the site for everyone."