"However, this does not mean that a provider of commercial sexual services in the past cannot be granted a visa, but that providing those services must not be the reason for granting the visa," Carley said.
In May 2018, the agency removed sex worker or escorts from its skilled employment list checker online.
The website had previously indicated that sex work/escort was skilled employment and applicants could claim points if they were paid above $36.44, had a recognised qualification or at least three years of relevant work experience.
The agency said figures on how many former sex workers had been issued with visas was not available.
"When a person who has provided commercial sexual services in the past applies for a visa, like any applicant, their visa will be assessed against the relevant immigration instructions," said Carley.
"Because providing commercial sexual services is illegal in many other countries, visa applicants who have provided such services in the past may have criminal convictions."
Foreign nationals who applied for a visa to come to New Zealand must be of good character, he said.
"People with criminal convictions or who have provided false or misleading information will generally not be granted a visa unless a character waiver is granted," Carley added.