Australia's offer to host this summer's British and Irish Lions tour has been turned down by the Lions board.

Rugby Australia had bid in January to host the series, with a pledge to have capacity crowds at the Test matches.

But following a meeting on Friday, this option has been declared unviable by the Lions management - with a final decision expected this month.

Four options remain: a UK and Ireland-based home "tour", a tour to South Africa with matches behind closed doors or with very limited crowds, a postponement until 2022, or a cancellation.

While a postponement would protect the Lions' touring ethos and would ensure fans could travel next summer, this is being resisted by some of the home unions.

The situation is complicated by the chief executives of the four home unions all sitting on the Lions board, and are therefore conflicted between what is best for the Lions and what is best for their individual union.

A home "tour" was given fresh impetus following UK Prime Minister Boris Johnson's announcement of England's roadmap out of lockdown - which could see capacity crowds in English stadiums by late June - but it needs substantial financial assurances to get off the ground.

Sources have therefore indicated a behind-closed-doors series against the Springboks is the marginal front-runner at this stage, with a final decision expected in the coming weeks.