Canada is asking for photographic proof from foreign strippers applying for working visas.
Canada says the policy is designed to protect women
An official at Canada's embassy in Mexico is quoted as saying "stage photographs" are mandatory before a visa can be issued.
But the Canadian immigration department denied exotic dancers were asked specifically for naked pictures.
Last month it was reported that Canada had issued a record number of visas to strippers to meet a national shortage.
"We don't ever ask for nude photographs,'' insisted Maria Iadinardi of the Federal Immigration Department, quoted by Canada's National Post.
But she said staff did sometimes ask for "stage photographs'' to prove that women hoping to be naked dancers in Canada had experience of the job.
"Stage photographs could be wearing a number of things,'' she said. "They could be wearing their full outfit or their costume of the day.''
The immigration department and Canadian lawyers said the policy was designed to protect women from exploitation.
Toronto immigration lawyer Mendel Green told the National Post: "To be very frank, from a practical standpoint, it makes sense if the young lady hasn't ever danced in the nude, to protect her.
"It's merely to ensure she knows what she's getting herself into.''
Ms Iadinardi said it was part of a wider effort to combat human trafficking by organised crime gangs who forced immigrants from poor countries into prostitution.