The pair fell for the property after renting the luxury executive rental,which costs about $1800 a night,for a holiday.
The deal,secured by Richardson&Wrench Noosa Principal Gillian McCauley,began when the McLarens walked into her Hastings Street office to enquire about purchasing a holiday home.
Despite the two-level home not being for sale,the couple eventually made an offer more than quadruple the price paid by its current owner,a UK-based expat,who paid $5.9 million in 2015,records show.
It comes just months afterJalna Dairy Foods was sold to French multinational dairy producer Lactalis.
The home,which can sleep up to eight people,has three car spaces as well as river access and a private jetty.
The price is a far cry from the $2,212,500 median house price in Noosa Heads,which jumped 41.4 per cent in the year to September on Domain data.