Investigators think they have found the cause of the hantavirus that killed three on a cruise ship. Two Argentine officials investigating the outbreak on the MV Hondius believe a Dutch couple may have contracted the virus during a bird watching trip in Argentina.

Investigators traced the suspected source of the outbreak to a landfill site visited by the couple during the excursion. Their leading theory is that the pair were exposed to rodents carrying the virus while visiting the rubbish dump.

It comes after Spain has said more than 20 British passengers will be brought home as soon as the ship arrives in Europe, although they may then have to isolate for as long as eight weeks.

The ship is now heading towards the Canary Islands after a British doctor on board fell seriously ill and had to be dramatically evacuated by air ambulance.

Health officials later confirmed the medic is now in a “stable condition”.