Greens senator Andrew Bartlett says legal advice shows he's eligible to sit in federal parliament.
Questions had been raised over whether the Queensland senator's Australian National University job at the time of his election breached section 44 of the constitution.
This disqualifies anyone who holds an office of profit under the Crown.
But Senator Bartlett on Sunday said legal advice showed he was in the clear.
"This legal advice reaffirms my view that university employees are not public servants under the control of a minister of the government," the senator said in a statement on Sunday.
Earlier this month he replaced disqualified Larissa Waters, who quit the Senate in July.
The Greens sough legal advice over Senator Bartlett's eligibility after the High Court found Liberal candidate Hollie Hughes in breach of the constitution for holding a job as a part-time member of the Administrative Appeals Tribunal.
Ms Hughes had been due to replace former minister Fiona Nash as a NSW coalition senator.
So far, nine federal MPs have fallen on their swords over the duel-citizenship fiasco.
All senators have until December 1 to provide a statement on their eligibility, family history and citizenship to be published on the senators' interests register.
The government wants lower house MPs to lodge their details by December 4.
Constitutional expert George Williams earlier said there were "significant unresolved questions" about Senator Bartlett's eligibility as the High Court had never dealt with the situation of a university employee.
