The former Detective was working on Operation Yewtree before quitting the force to take part in Big Brother, and now his ex bosses worry about what details he may give away.
According to the Daily Mail, up to two police officers are being paid to watch the show every night, as well as the live feed and to monitor the show's official Twitter account.
A source told the newspaper: "This has to be the cushiest police job ever. Questions have to be asked whether this is really necessary."
Meanwhile, both Channel 5 and Dan have come under fire for his inclusion in the series.
Lawyer Liz Dux, which represents 62 alleged victims of Jimmy Savile, commented: "This is extremely traumatic for some of the victims.
"They have poured their hearts out to this detective – some of them disclosing details which they haven’t yet told their family."
She added: "Now they fear that him appearing on Big Brother will mean that some highly confidential information will be revealed. It’s not just the fear of what might come out on nation television, it’s also the fear of what this detective might be telling other housemates when the cameras are not on him which is giving them such torment."