A good Samaritan has gone on a one-man crusade to reunite a mystery Australian couple with their 4000 cruise ship holiday snaps after finding their memory card in Stockholm last month.

Marc Biskup has taken to social media to track down the pair posting on his blog a plea saying: 'PLEASE HELP FINDING THOSE TWO AUSTRALIANS!'

He explained that he and his girlfriend went on a short trip to Stockholm at the end of May, and on their last day there they found a Micro SD card. On the memory card there were over 4000 pictures and a couple of videos.

The mystery Australian couple (pictured) were on holidays in Stockholm and Copenhagen

The couple went on a cruise from Copenhagen to Tallinn, St. Petersburg, Helsinki and Stockholm

From what he could learn from the photos and videos, the couple are from Australia - or at least the man is.

'They (the photographs) belong to a couple on a cruise from Copenhagen to Tallinn, St.Petersburg, Helsinki and Stockholm,' Mr Biskup wrote.

'Stockholm was their last port before returning to Copenhagen, so basically there is every single photo of their holidays on this SD card. We want them to get it back - please help us finding them.'

Marc Biskup, pictured with his girlfriend Sarah, is determined to find the mystery Australian couple

Marc Biskup found the couple's memory card in this area of Stockholm in Sweden at the end of May

After some more detective work Mr Biskup was able to piece together that the couple had been on a cruise for 11 nights, starting from Copenhagen ‘probably on May 24’.

They stayed at least two more days in Copenhagen before the cruise. The tour ended in Copenhagen on June 4.

The couple travelled on a ship called 'Regal Princess' of Princess Cruises. He also posted an itinerary of the type of cruise it would have been.

Mr Biskup believes that one of the couple is connected to Deakin University of Melbourne

The couple have over 4000 pictures and a couple of videos on their memory card

He also believed that one of them could be connected to Deakin University of Melbourne.

'Unfortunately, we did not have any luck in contacting Princess Cruises or Deakin University,' wrote Biskup.

'We hope for an email every day. So you are our last hope. Please spread this blog post and help us to find the two Aussies so that we can send them their holiday memories.

'I think they would be really happy.'

If you have any information please email Marc on: schreibdochmal@marcbiskup.de