The Public Service Commission will review the Accredited Employer Work Visa scheme's processes after a whistleblower came forward with allegations, Immigration Minister Andrew Little says.

At a stand-up just after 5pm, Little told reporters he received an anonymous letter on Tuesday night, which came from an internal whistleblower.

"The particular allegations were that some checks on employers were not being made, and some checks as part of the job check process were not being made.

"I spoke to the Public Service Commission yesterday and to the Ministry for Business, Innovation and Employment yesterday about that.

"There was enough in the letter, not withstanding it was anonymous, that led me to believe that it was important that I assure myself that the rules for processing those, particularly Accredited Employer Work Visa applications, are being done thoroughly and that the allegations in the letter are investigated."....