A Norwegian flight was forced to turn around and land back from where it had taken off because of malfunctioning toilets – despite having 85 plumbers on board.

The bizarre incident unfolded on Saturday (27 January), when flight DY1156 was forced to turn around and land at Oslo Gardermoen airport just 20 minutes into its trip from the Norwegian capital to Munich.

"It is true that DY1156, which was to fly from Oslo to Munich, had to return to Oslo again when they found an issue with the toilets on board," Norwegian communications adviser Fatima Elkadi told Norwegian news site Dagbladet.

Data from FlightRadar24.com shows the Boeing 737 aircraft had barely reached the Swedish border when the issue arose, forcing it to circle four times over Hedmark, approximately 220km north of Oslo, to get rid of excess fuel before landing back at its origin.

The plumbers on board, 65 of whom worked for the company Rørkjøp, said they would have liked to help but their quest was hampered by the fact the plane was travelling at an altitude of 10,000m when the issue emerged.

"We would have liked to fix the restrooms, but unfortunately it had to be done from the outside and we didn't risk sending a plumber to work at 10,000m," Rørkjøp CEO Frank Olsen told Dagbladet.

"There was a good atmosphere in the plane, what with the irony about the broken toilets."

The aircraft, which had taken off at 9.34am local time (8,34am GMT), was quickly repaired after landing at Gardermoen and resumed its flight to Munich as planned, landing in Germany shortly after 12pm.