Anti-corruption authorities said this week they had detained five people and identified two others still at large, suspected of involvement in an alleged $US100 million ($A153 million) plot to control procurement at nuclear agency Energoatom and other state enterprises.
Ukraine's biggest wartime graft scandal comes as the country's outmanned and under-equipped troops are struggling to fend off grinding Russian advances on the battlefield.
Zelenskiy, whose former business associate from his comedy career is among the suspects, said in a video address that corruption in the energy sector - weakened by regular Russian air strikes on infrastructure - was "absolutely unacceptable".
Shortly after his remarks, Prime Minister Yulia Svyrydenko submitted a request for parliament to dismiss Energy Minister Svitlana Hrynchuk and Justice Minister German Galushchenko, Hrynchuk's predecessor in the post.
Galushchenko has not been identified as one of the seven suspects announced this week, but a former advisor of Galushchenko's has been.
He has denied wrongdoing.
Galushchenko's voice was among those heard in a recorded conversation with some of the suspects in the case that was released by the National Anti-Corruption Bureau of Ukraine, according to a source familiar with the matter.
The minister did not respond to a Reuters request for additional comment.
Hrynchuk, who earlier on Wednesday said she had submitted her resignation, has denied any wrongdoing.
The probe by anti-corruption body NABU, details of which have been incrementally released in sleekly produced videos featuring the lead detective, is the latest revelation of alleged graft that has plagued Ukraine's wartime government.
Showing progress in fighting corruption is central to Ukraine's bid for membership in the European Union, which officials consider key to escaping Russia's influence.
Accusations of kickbacks in the energy sector are particularly sensitive among Ukrainians, who are facing daily power outages ahead of winter as a result of massive Russian attacks on infrastructure.
It could also dampen enthusiasm among donors who have provided critical assistance to Ukraine's hobbled energy sector.
Speaking on local television, MP Serhiy Nahorniak, a member of parliament's energy committee, said he had already been contacted by donors refusing to provide a transformer for Ukraine's battered Sumy region.
"Having read the news, they said, 'We think you can afford more than one transformer,'" he told the Kyiv24 channel, without specifying who the donors were.
Earlier this year, Zelenskiy tried to limit the powers of Ukraine's anti-corruption authorities but rowed back on those changes after rare street protests and an outcry from European partners.
Political opponents accused him of trying to scuttle the activities of corruption-fighting bodies to protect his associates, which Zelenskiy strongly denies.
One of the seven suspects identified by prosecutors is Timur Mindich.
He is a co-owner of the influential Kvartal 95 television studio, which produced the popular sitcom that brought Zelenskiy to fame as a comedian before he launched his political career with a successful campaign for president in 2019.
