
A collection of sports cards estimated to be worth more than $1million has been discovered in an abandoned warehouse in Detroit.

Millions of the Topps cards were packed away in dust-covered crates, with thousands more strewn over the floor of the derelict building.

The mint-condition collectibles, dating from the late 1980s and 90s, were discovered by a team of urban explorers whose hobby is to venture into forgotten man-made structures.

While only estimated to be individually worth between 99 cents and $5.99, the collective haul of hundreds of cases would potentially fetch millions if ever put on the market.

Discovery: These urban explorers venture into abandoned buildings in search of remnants of its past, in this case finding millions of sports cards

Sporting history: Thousands of the Topps cards featuring stars of US sports in the 1980s and 1990s are scattered across the floor of the derelict building

The sports cards technically belong to whoever owns the building or possibly another company who paid for them to be stored there under contract.

But the absence of many doors and windows in the once-thriving factory points to the fact that no-one official has been on the premises for decades.

The only people aware of the treasure trove are the handful of explorers who know of its existence, some occasionally seeking out valuable cards to sell themselves online.

At least one man, who goes by the name of Slanks, regularly frequents the factory to find cards to sell, claiming it has been his primary source of income.

Mint condition: Many of the cards, many featuring celebrated stars of Major League Baseball, are still in their original sheet format

Shipment: Case loads of the collectible sport cards have never been opened suggesting the cards were mid-shipment when they were left in this Detroit warehouse

Untouched: The crates of sports cards, which contain anything from rare collectibles, to full sports teams of the time, have been lying in the factory since it closed

The vast bundles contain full teams from all of the Major League Baseball of the time as well as hockey cards from the NHL and Ontario Hockey League and even NASCAR.

Some of the boxes are full of complete team sets with one uncovered set showing the full squad from the 1990 Detroit Tigers.

'Made in Taiwan' and 'packaged in the USA' is printed on the boxes, suggesting the abandoned factory could have been used as a packaging facility, shutting down before these boxes had a chance to be shipped.

They are packed as though they had just been delivered from their manufacturing plant and were awaiting further shipment but never made their final journey.

The struggles of Motor City are well known with the city's issues with money, crime, and decay a focal point of its recent history. But its crumbling remains are also said to be behind a spike in tourists who visit the city to visit its ruins.

Former prestigious sites like the Grand Michigan Central Station and the decrepit Michigan Theater have made the city a top spot for 'Urbex'.

Derelict: The Fisher Body Plant, an automobile factory from the early 1900s, lies abandoned on the outskirts of Detroit and is popular with urban explorers

Snapshot into the past: The grand Michigan Central Station is an example of one of the grand buildings which now stands empty in the city

Hollow: An abandoned highrise tower is one of the many derelict scenes visited and investigated by urban explorers in Michigan

Inside: Not every abandoned building yields a valuable discovery with this interior shot showing just a few signs of the life once lived there