Deputy Prime Minister Bekir Bozdag reiterated his criticism that the case, due to hold court proceedings in New York later Monday, "has no legal basis," according to the state-run Anadolu news agency.
Zarrab was arrested in the US last year. Prosecutors in the US allege he was behind a scheme to evade sanctions on Iran worth hundreds of millions of dollars.
Charges have also been brought against a Turkish banker and a former Turkish minister.
The case has strained ties between the US and Turkey, which are both NATO members, with Turkish politicians increasingly critical of the US judiciary system in particular.
Last week, Bozdag said the case was "a clear plot against Turkey."
Zarrab was arrested in the US last year. Prosecutors in the US allege he was behind a scheme to evade sanctions on Iran worth hundreds of millions of dollars.
Charges have also been brought against a Turkish banker and a former Turkish minister.
The case has strained ties between the US and Turkey, which are both NATO members, with Turkish politicians increasingly critical of the US judiciary system in particular.
Last week, Bozdag said the case was "a clear plot against Turkey."