Image copyright Reasons My Son Is Crying

Tom Hanks or Bill Murray? Bill Hanks, Tom Murray? Bill? Tom? Tom/Bill? It's a question that the internet has been wrestling with for days.

The truth is we've known the correct answer since 2013, when it was originally posted on the Reasons My Son is Crying Facebook page.

But that hasn't stopped people arguing about it all over again.

It's definitely NOT Tom Hanks

We contacted Laura DiMichele-Ross - the woman whose wailing son is the true star of this photo - in the hope of clearing the whole thing up once and for all.

"It's definitely Bill," is her answer.

Image copyright Laura DiMichele-Ross

The picture was taken by her husband Adam at the Alfred Dunhill Links golf competition at St Andrews in October 2012.

"Bill's a good person to follow as he jokes around and takes photos with fans," she says.

"My son took one look at him and started bawling," she explains, before mentioning another picture taken on the day where "he's not crying and just smiling normally".

Image copyright Laura DiMichele-Ross

At the time her son, Alexander, was eight months old. Now four-and-a-half, he loves Ghostbusters but "doesn't know who Bill is," Laura says.

He's also blissfully unaware of his role on an internet meme, although Laura promises they're saving that for his "internet security project" or something similar when he's old enough.

As further proof, Laura sent us a copy of the photo that they had signed by Bill Murray when they saw him again in 2014.

Image copyright Adam Ross Image caption "Bill got a good laugh when he showed it to Huey Lewis"

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We also contacted Hanks via his Twitter account to get confirmation that it's not him.

Further evidence was supplied by Matthew Soper.

Image copyright @SoperMatthew

His friend Sarah Chastain took this picture of a man who is definitely Bill Murray on the same day.

Image copyright Sarah Chastain Image caption Definitely Bill Murray. Definitely NOT Tom Hanks

How did it become a meme (again)?

After the photo was taken, it made the cover of the local paper, The Perthshire Advertiser and was shared with friends.

It was the decision in May 2013 to share it with the Reasons My Son is Crying Facebook page that started it. Laura "was awoken the next morning to be told it had made the Huffington Post".

Since then she reckons it resurfaces every couple of months when she's tagged by people she's not seen since school.

The latest explosion came when she was contacted by Courtney Cox from NBC.

"I thought it was someone pretending to be 'Courteney Cox' from Friends, so I ignored the request. They posted it on the Today Show page and it went from there."

Image copyright Today Show

Laura is now in the process of getting back in touch with NBC.

Other important questions answered

Laura's favourite Bill Murray films: "Ghostbusters and Lost in Translation."

Laura's favourite comment on the photo: "It's definitely Tom Hanks because that's his wife in the photo."

Has Laura met Tom Hanks: "I haven't but I'd love to. He's a legend as well."

How to tell Bill Murray from Tom Hanks

Image copyright EPA

Name: Bill Murray

Age: 66

He's the one in: Caddyshack, Ghostbusters, Groundhog Day, Lost in Translation

Distinguishing features: Hangdog face, grumpy demeanour, laconic delivery

Image copyright AP

Name: Tom Hanks

Age: 60

He's the one in: Splash, Saving Private Ryan, Forrest Gump, The Da Vinci Code

Distinguishing features: The American everyman, amiable, boyish charm

Was starring in Nora Ephron's Lucky Guy on Broadway in May 2013

If you would like to share this story with a friend who is doing it wrong, try one of these lines:

People are saying it's Tom Hanks even though the woman who is in the photo says it's definitely Bill Murray

Nope, definitely Bill Murray

SRSLY, How can you even think this is Tom Hanks?

We hope the matter is now settled as it was threatening to get a bit like #TheDress argument, which we can safely say "got a bit out of hand" and practically brought the internet to a standstill in February 2015.

BBC Trending explain the "What colour is the dress?" meme

Media playback is unsupported on your device Media caption Is it white and gold? Or is it black and blue? David Sillito explains

By Alex Murray, BBC's UGC & Social News team