A 41-year-old man who attempted to swim across Cook Strait has reportedly died just after completing the feat of endurance. 

Nick Hobson swam across the strait, but according to the Facebook group Wellington Ocean Swimmers, died shortly afterwards on Friday night. 

"It is with great regret and huge sadness we need to share the news that our friend Nick Hobson passed away last night following his swim across the Cook Strait," a poster wrote on the message board. 

"His crew, and the rescue helicopter, made every effort to resuscitate him, but they were unsuccessful. There is very little else to say at this stage, as the shock and sadness hit us." 

Photos and video shared by the group had showed Hobson swimming with dolphins on his journey. 

A police media spokesman told Stuff that they responded to a report of a sudden death at Mana on Friday evening. 

There was no further information on the cause of death. 

Tributes from international organisations have emerged online for Hobson including from the Marathon Swimmers Federation, the British Octopush (underwater hockey) Association and the International Swimming Hall of Fame. 

He was acknowledged for his swim across Lake Michigan in 2018 and his involvement on the organising committee for 2006 CMAS Underwater Water Hockey World Championships in Sheffield. 

At least 130 people have swum the approximately 23km distance across the strait, according to a website chronicling attempts across the dangerous waterway between the North and South Islands. 

- by RNZ