Updated 9am

Swimmer Neil Agius was forced to abandon his world record-breaking challenge early on Tuesday because of multiple jellyfish stings.

In a post on Facebook, his team said Agius was forced to abandon the challenge at 3.56am, around a quarter of the way through his attempt.

The decision was taken in full consultation with the medical team onboard one of the two support vessels. 

His team said he entered a swarm of jellyfish around 46km into the swim in the Mallorca - Ibiza channel at around 1am.

The Olympian began his attempt on Monday to cross 160 kilometres of open water without any assistance, breaking a record that, according to his team, he currently holds.

After nearly four hours, multiple stings and several attempts to resume the swim, the swimmer endured too much swelling and pain and he voluntarily decided that the safest thing was to abandon the plan.

“It is so sad to see all that hard work we put into this challenge come to such a premature conclusion, I was feeling strong and ready to go the distance but fate had other plans," Neil said.

He added that this was the sport he chose. It depended on many variables "some we can be in control of, others unfortunately not".

The athlete and his team had plans in place for jellyfish swarms, which had already been identified as the leading threat to the challenge, as large swarms are regularly sighted in the Mediterranean. 

Global warming and overfishing are believed to be the leading causes of rising jellyfish numbers across the globe. 

He thanked all supporters who were rooting for the team and backed it up over the last 10 months.

"The real challenge for ocean conservation still stands, I will be back," he said.

The fleet has now turned back to Mallorca where a news conference will be held.

BRND WGN CEO Peter Grech who was accompanying the swimmer said: "It was a very tough moment to witness, but it was the only call to take. Neil Agius is an exemplary athlete, an honest leader and a beautiful human being. It’s sad to see his dream wash away like this after all that hard work but the impact was not based on the destination but rather on getting the message across which I believe he managed successfully. The journey is not over."

Agius's 2021 attempt to break the world record for the longest ocean swim, which saw him travel 125.7km in 52 hours and 10 minutes from Linosa, Lampedusa to Xlendi, Gozo has just been verified by the Marathon Swimmers Federation.

Through his challenge this year, Agius hoped to raise awareness and lobby governments to sign up for, and properly implement the United Nations Treaty of the High Seas. 

Adopted in New York on June 19, the treaty establishes area-based management tools for ocean preservation, including marine protected areas, to conserve and sustainably manage vital habitats and species.  

According to the UN, currently only about one per cent of the high seas are protected. 

The adopted agreement will be open for signature at United Nations Headquarters in New York for two years from September 20, the day after the 2023 Sustainable Development Goals Summit. It will enter into force after ratification by 60 states.