The founder of The Fans Museum has spoken of his sadness and frustration after priceless memorabilia was stolen.
The museum, based in the former Monkwearmouth Station Museum, has been founded by Michael Ganley to allow football supporters from all over the country and even abroad to view historic pieces of sporting memorabilia.
Mr Ganley was formally handed the keys to the building at the end of last year, after council bosses agreed to let the site be used by him and his team.
But now Mr Ganley, a devoted fan of Sunderland AFC, has spoken of his shock after finding that the building was targeted by burglars on Wednesday night.
Mr Ganley initially thought that nothing had been taken but has since discovered that a playing contract for former star Winston Young, who passed away at the weekend, a medal from the from 1988 centenary and £140 cash - for a charity prize to help raise money for their Alzheimers & Dementia program - had been stolen.
He said: "Last night we thought that nothing was taken, but then I have been told this morning that a players contract with a medal have been taken so we are a bit more disheartened.
"That player was called Winston Young and he passed away on Sunday night.
"So this is a piece that means a bit more to us.
"I am fuming about it, but obviously business continues."
The museum, which also supports a variety of worthy causes in the city including former servicemen from the Veterans in Crisis group, looks set to open in the summer.
Mr Ganley added: "If things like this were to happen when we are fully operational it would have a huge impact on us.
"Insurance companies are very sceptical, what we're doing is something unique.
"It is still coming from my own pocket.
"We want to do something good for my home town and we are trying to help as much as we possibly can, but if things like this were to continue I would basically have to shut the doors and take it to a different venue and Sunderland wouldn't be the venue.
"I am a fan and I am a Sunderland person through and through, but we have got to look at security.
"We shouldn't have to, but it is life now.
"It is my personal collection and it is all detrimental to myself."
A Northumbria Police spokesman said: "Police received a report of intruders at the museum on North Bridge Street in Sunderland.
"Officers attended and found that entry had been gained to the property by smashing a rear window.
"Inquiries into the burglary are ongoing and anyone with any information, or anyone who saw anyone acting suspiciously, is asked to contact police on 101 quoting log 899 11/04/18."