Scandal-plagued convenience store chain 7-Eleven and its franchisees are under investigation from the Victorian and NSW state governments over their alleged failure to pay state payroll tax.

It's another blow for the company that was at the centre of a major wage fraud scandal last year after an investigation by Fairfax Media revealed 7-Eleven workers were being paid as little as $5 per hour.

The separate state government investigations into 7-Eleven were revealed in a freedom of information request under NSW transparency laws lodged by Labor MLC Daniel Mookhey to the Office of State Revenue.

The documents uncovered through the request revealed that Victoria's State Revenue began an investigation into the Melbourne-headquartered 7-Eleven and its franchisees operating in Victoria over concerns about payroll tax compliance.