The truth behind Australia's recently retired opener David Warner's missing baggy green has finally been revealed.

Warner had lost the bag containing his Test cap, the baggy green, just days before his final Test in Sydney against Pakistan and made a passionate plea on social media to get it back, even offering a reward for whoever returns it.

It became almost a national issue in Australia with even their prime minister Anthony Albanese asking the perpetrator to return the bag.

But now Sydney Morning Herald has revealed that the bag containing Warner's Test cap had never left the Intercontinental hotel in Double Bay and was right there with the rest of the assorted baggage of the team.

The backpack had been packed in a "half coffin" cricket bag, commonly used to carry smaller items of equipment for players and staff, rather than one of three bigger "full coffin" bags that Warner had identified as most likely to contain the backpack.

Confusion about whether the backpack was in a half or full coffin bag contributed to the inability of Warner, his wife Candice or members of team staff to locate the bag once the cricketer went searching for his baggy green caps ahead of the SCG Test.

The bag that contained Warner's backpack and caps was in another part of the room to his other bags, and was placed with its "David Warner" label tucked underneath, unseen as increasingly frantic searches were conducted in the lead-up to day one of the SCG Test.

This also meant there was some uncertainty about whether all bags had been searched, as Warner went public to say his backpack and "baggy greens" were missing.

Ultimately, another check through all 64 bags conducted by team manager Catherine Wightman on January 4 and Warner's backpack was found in time for him to have his caps back to wear on the final two days of his last Test.