"I was very unwell with a bug."

Wiffen was due to be a flag bearer for Ireland after his hugely successful Games, where he won a gold medal in the 800m freestyle and a bronze medal in the 1500m freestyle.

The 23-year-old, however, was absent from the closing ceremony and later revealed on social media that he had been taken to the hospital in Paris on Sunday afternoon.

Wiffen was feeling unwell due to a bug. He is currently being treated and says he is now feeling better, however.

Wiffen was due to be a flag bearer for Ireland at the closing ceremony, alongside Mona McSharry, who won bronze at the Games.

Rowing gold medalist Fintan McCarthy stepped in to replace Wiffen at the ceremony.

"Thanks everyone who reached out," Wiffen posted on social media.

"I’m incredibly disappointed to miss out on the opportunity to be flag bearer last night.

"Yesterday I rushed to hospital (sic) as I was very unwell with a bug that I am being treated for, and am feeling better now.

"I hope everyone enjoys the evening and I hope to be well enough to seeing everyone when we get home."

Wiffen swam in the 10km marathon race in the Seine river in Paris on Friday and it is possible that he contracted the bug during the swim.

The Irish swimmer finished a respectable 18th in the race but, immediately after the event, vowed never to compete in an open water race again.

At the time of writing, it is unclear if Wiffen will be well enough to attend the homecoming in Dublin for Team Ireland on Monday afternoon.