The 22-year-old was found to have committed a whereabouts anti-doping rule violation, following three filing failures within the space of a year.

Under the whereabouts system, elite athletes are required to provide their location for one hour every day so they can be located for testing and maintain the accuracy of their whereabouts information at all times.

ASADA has claimed Poort failed on two occasions to submit his information on time.

On the third occasion, ASADA attempted to test Poort outside his designated hour, only to discover that he had not updated his whereabouts to take account of travel plans.

The maximum sanction for a whereabouts violation is two years, but ASADA determined that Poort's actions were "not a deliberate attempt to deceive anti-doping authorities and that his level of fault did not warrant the maximum period of time".

The Australian competed at both London 2012 and Rio 2016, finishing 18th in the 1,500 metre freestyle and 21st in the 10 kilometres open water event respectively. 

"Understanding and being compliant with the whereabouts system is part and parcel of being an elite athlete," said acting ASADA chief executive, Judith Lind.

"Without whereabouts information, it would be almost impossible to conduct out-of-competition testing of athletes, which is an integral part of any effective programme to catch cheats.

"Whether they were intentional or not, filing failures are serious because they can prevent anti-doping organisations from being able to plan or carry out testing missions.

"ASADA does everything it can to make this system as simple as possible, and athletes can easily make changes to their whereabouts information online.

"It is crucial that athletes understand the importance of maintaining accurate whereabouts information and the impact that these failures can have on their career."

As a result of the sanction, Poort is ineligible to compete in any sport until September 5, 2018.

Poort has waived his right to appeal but the World Anti-Doping Agency and International Swimming Federation may still seek to appeal the decision should they wish to.