Rockstar Games is "hard at the work on future projects" which will be "revealed soon", according to the latest financial report from parent company Take-Two.
Given how much money GTA Online is making, this likely wouldn't be the case if the studio were releasing a new game soon.
Take-Two's list of upcoming games for the current financial year ending 31 March 2017 includes Mafia 3, Civilisation 6, WWE 2K17 and NBA2K17.
No further details were offered on whatever it is Rockstar has in the works, or whether any announcement would be made at next month's E3 trade show in Los Angeles.
The news will ramp up speculation regarding a follow-up to 2010 classic Red Dead Redemption – which is believed to be Rockstar's next game.
Were Rockstar to make an appearance at E3, which they rarely do, it would likely be during Sony's press conference.