Former census officers yesterday spelt out the ridiculously tough regulations which they said forced staff to fake answers - and one claimed management knew what was going on.
"Let's say a frontline officer approaches a family of four," one ex-officer said in a radio phone-in show. "The officer needs to interview each household member face-to-face for it to be considered a successful case."
He said this was often impossible within any reasonable time frame because usually at least one person was not present. And he pointed out some households could include multiple families in subdivided flats, all of whom had to be interviewed.
He added that the department realised the face-to-face rule was not always feasible - resulting in an unwritten rule that if a household member could provide information on absent members, then this, too, could be considered a successful case.
However, he said, the reality was that some members of the household would not be able to provide these details, so officers would either fake answers, perhaps after guiding interviewees to give a rough estimate.
"And let's say there are four families living in a subdivided flat and each family has four members, it is not considered a successful case even if you manage to talk to only 15 of the 16 members," he said.
"If this system is not changed, it [the department] can never provide accurate statistics."
Another former officer said in the same programme that when he worked for the department in 1990 the officers were instructed to complete 60 to 70 cases in one day, an impossible task. Even his superior could only manage about 20 a day, he said.
The department would insult teams who could not meet targets and that helped push officers to make up answers, he added.
A spokeswoman for the Census and Statistics Department requested more time to respond to questions about whether regulations were too tough.