The series 11 creative director claimed that spots in the two-week run, which will air at the end of the summer, are still up for grabs.
"We'll decide in a few weeks' time," he told the DS forums. "Always up for suggestions but there are a limited number of slots.
"There's a team working on it now - and there is an ongoing healthy debate about who we want to see in those last two weeks. There are loads of great housemates to choose from."
It was confirmed earlier this month that 12 former housemates will join the Big Brother 11 winner inside the house at the end of the series, where they will compete for the crown of Ultimate Champion. Former winners such as Craig Phillips, Brian Dowling and Nadia Almada are expected to take part in the competition.