Search for missing Barclays Bank customer John Evans who is owed $350,000 by UK court

The UK supreme court is holding £200,000 ($A350,000 of Mr Evans’ money at its chancery division, waiting for him or a family member to come forward and claim the cash.

However, no-one knows who Mr Evans is – much less who his family may be.

The money will remain there until someone can prove they are the John Evans, or that they are related to the mystery man.

London financial firm, Green & Parish Limited, makes a business out of locating unclaimed assets but they’ve been unable to track down Mr Evans so far.

According to Wales Online, all investigators know of Mr Evans is that he was a customer at Barclays Bank Exchange Buildings, in Cardiff Docks, Wales, in the 1970s.

However, the Barclays branch closed in 1980, and its bank records were destroyed around that time.

Green & Parish investigators suspect that Mr Evans has long since passed away and that his family are owed this unexpected fortune.

“Our working theory, as so many years have elapsed, is that Mr Evans will have died in the intervening years and these funds will be due to his estate,” a company spokesperson told Wales Online.

They also said “there are simply hundreds of John Evans” and didn’t expect to ever find this particular one.

“We have been trawling through death records for John Evans in the Cardiff area but, as you can imagine, there are simply hundreds of John Evans who have died in the Cardiff area. We do not have a middle name or perhaps there was no middle name.

“All death certificates and grants of probate give home addresses for deceased John Evans but no banking details and, therefore, it is impossible to definitively link any Mr Evans to this branch.”

In order to be taken seriously by investigators, John Evans or a family member must be able to prove their connection by producing an old bank statement.

Whatever passes as definitive proof will be up to the judge‘s discretion.