GTA Online's The Cayo Perico Heist update reportedly contains mysterious textures that could be from Grand Theft Auto 6. The discovery was shared by X (Twitter) user Lucas7yoshi_RS. According to the data miner, the textures contain references to physically based rendering (PBR), a technology that was used in Red Dead Redemption 2 and will likely be used in GTA 6. Lucas7yoshi_RS believes that the discovered textures were either ported from Grand Theft Auto 6 or created by an artist working on the upcoming game.
It's worth noting that YouTuber LegacyKillaHD recently claimed to have revealed the voice actors for Jason and Lucia in GTA 6. He also stated that basketball and American football will be playable in the online portion of the game.