MPs are not allowed to employ their partner, husband or wife in or outside Parliament.
A spokeswoman for Parliamentary Service, the in-house watchdog, confirmed Speaker of the House David Carter had "referred an issue to us and we are looking at it, but that's between us and the Speaker's office. I'm not going to say any more than that".
She said there was nothing in its files to indicate that Mr James was Mr O'Rourke's partner.
Mr O'Rourke last month confirmed he employed Mr James after the 2011 election but denied Mr James was his partner. Mr James also denied the relationship.
Mr Rourke this week said he was "not interested in people making allegations".
"They are not relevant to anything as far as I'm concerned, it's just politically motivated nonsense."
Mr O'Rourke also said rules around MPs employing their spouses or partners were "something we looked at very closely after the election ... . and we understand the situation".
"Stephen is definitely not my partner, he lives at a separate address in Christchurch."
Mr O'Rourke and Mr James were listed as living at the same address in the 2011 electoral roll, but Mr James is listed as living at a separate address in last year's roll.
However, Herald investigations reveal both addresses apply to the same property - Mr O'Rourke's home.
On Tuesday Mr James emerged from the Mt Pleasant property to check the mailbox. He was later seen inside the property but refused to answer the door.
Mr O'Rourke later confirmed Mr James lived at the same property.
"Yes, there's a flat attached to my home with separate bedroom and kitchenette and an ensuite and so on. It's separate accommodation."
Online records show Mr O'Rourke's property is listed as a single dwelling. Mr O'Rourke later said Mr James lived in "a room that's been separated from the house and used as a bedsit".
"It's not a formal subdivision ... I did upgrade it a couple of years ago and that's the same time that we got the separate letterbox."
He reiterated that he and Mr James were not partners.
"We're deliberately not partners and whatever it takes to convince people we're not partners, that's what we'll do. We don't intend to be partners, we've agreed not to be partners, we don't do the things that partners do, so we're not partners."
He said Parliamentary Service had not spoken to him about Mr James.
"I haven't heard anything about a complaint so as far as I'm concerned a complaint has not been made."
Mr Simpson said his complaint was based on information about Mr O'Rourke he received from an MP.
NZ First leader Winston Peters said he understood Mr O'Rourke was not in a relationship with Mr James.
By Adam Bennett of The New Zealand Herald; additional reporting by Kurt Bayer of APNZ
