The Olympic diving pool has turned green and no one knows why

A strange and unsettling thing happened to the Olympic diving pool on Tuesday. The water, which had been a lovely light blue colour at the start of the Rio 2016 Games, turned a murky green colour.

The inexplicable transformation happened just in time for the women's synchronised 10-metre platform diving competition. Lucky ladies, eh...

And the cause of the swampy shade? Well, erm, reassuringly, no one seems to know...

Olympic organisers said water tests were carried out at the Maria Lenk Aquatics Centre and there was no risk to athletes, but the cause of the colour change is currently under investigation.

Team GB medalist Tom Daley, who won bronze alongside Dan Goodfellow in the diving pool on Monday, tweeted about the water's weird and not-so-wonderful metamorphosis.

And, naturally, the internet has set about finding the root of the problem: