Fathimath Shamnaz Ali Saleem was arrested along with her sister and another person last month in the capital Male and stood down from her post shortly afterwards.
Local media reported she was accused of performing «black magic» on President Mohamed Muizzu to win favour from his new administration.
Police had asked for an extension of her detention twice, but on Saturday they had no reason to hold her any longer — although the case was still ongoing.
«The investigation is still pending,» a police official, speaking on condition of anonymity, told AFP in Male.
Police and authorities have not confirmed or denied the nature of the allegations against Shamnaz, and a criminal court has heard the case behind closed doors.
Her position was an important job in a nation on the frontlines of the climate crisis, with UN environment experts warning rising seas could make it virtually uninhabitable by the end of the century.
Sorcery is not a criminal offence under the Maldivian penal code, but it does carry a six-month jail sentence under Islamic law.
People across the archipelago widely practice traditional ceremonies, believing they can win favours and curse opponents.
A 62-year-old woman was stabbed to death by three neighbours on Manadhoo last year after she was accused of conducting black magic ceremonies after a lengthy police investigation.
In 2012, police cracked down on an opposition political rally after accusing organisers of throwing a «cursed rooster» at officers raiding their offices.