The Channel 4 reality series traditionally kicks off towards the end of May, but the network is believed to have delayed this year's launch because a clash with Talent would be too risky. Ratings for Big Brother 8 dropped below 3 million viewers when it competed against the ITV1 show last summer.
The new series is expected to last for 13 weeks, with the final airing on September 5.
Insiders have admitted that this year's run could be "make or break" for the show, though suggestions that the 2007 series was a flop have been played down.
One source told the Daily Star: "Last year was a success. We had superbitch Charley, the Ziggy and Chanelle romance, the sexy 'Samanda' twins and of course dopey Brian who ended up winning. But that was last summer. The new show is what matters. Big Brother 9 is make or break."