In Fishy Business, Marius Kindus was a furrier who was caught by Biggles for smuggling furs. A man of forty-seven at the time of the crime, Kindus had been born in London of Latvia parents. Married with no children, Findus lived in a flat over his expensive shop in Mayfair. A furrier of repute, he was patronized by wealthy clients. He often spent his weekends at a country house in Wivenhoe, Essex where he kept a boat, the Scandik. A member of the Tunny Fishers Club, Kindus apparently had some success in his hobby of deep sea fishing, having been featured in a newspaper for landing a tunny weighing 650 lbs.
When Lutenski, another furrier, had spotted one Lady Branding wearing a mink coat made from furs which he bought from Leningrad but which were never delivered to him, he set out to discover its origins. Hearing from Lady Branding that she had bought it from Marius Kindus, he next confronted Kindus about the furs. Findus claimed he had bought it at a private show in a flat at Parklane. Investigations by Lutenski and, later, Biggles showed that Findus had lied, as the flat had been vacant for a long time.
Biggles decided that Kindus' movements merited a closer look. When Kindus next put to sea in the Scandik for a deep sea fishing trip, Biggles sent Algy and Bertie to shadow the ship in the Auster. Bertie reported that the Scandik had been spotted lying less than half a mile from a Latvian drifter. Finding this suspicious, Biggles waited for the Scandik to pull into Wivenhoe and then demanded to examine a tunny fish which Kindus was landing. Despite his protestations, Biggles cut into the fish and found a collection of expensive furs rolled up in oiled silk.