Port-au-Prince chief prosecutor Bedford Claude had previously invited Henry to testify on the case, citing evidence that a key assassination suspect had called him within hours of the murder. Henry was scheduled to testify Tuesday morning.
This suspect, the former head of the Haitian Ministry of Justice Joseph Felix Badio, is said to be on the run.
Claude told CNN he was discussing possible charges against Henry with the judge.
The late President Moise was brutally killed in an attack on his private residence on July 7. The investigation into his murder is ongoing and has revealed dozens of suspects, including US and Colombian citizens.
Moise’s death sparked a weeks-long standoff over the country’s leadership between the newly appointed Henry – a neurologist by training – and acting Prime Minister Claude Joseph, before Henry finally took power.