Thomas Schaefer, the finance minister of Germany's Hesse state, has committed suicide apparently after becoming "deeply worried" over how to cope with the economic fallout from the coronavirus, state premier Volker Bouffier said on Sunday.

Schaefer, 54, was found dead near a railway track on Saturday. The Wiesbaden prosecution's office said they believe he died by suicide.

"We are in shock, we are in disbelief and above all we are immensely sad," Bouffier said in a recorded statement.

Police and prosecutors said factors, including the questioning of witnesses and their own observations at the scene, led them to conclude that Schaefer killed himself.     

Hesse is home to Germany's financial capital Frankfurt, where major lenders such as Deutsche Bank and Commerzbank have their headquarters. The European Central Bank is also located in Frankfurt.     

A visibly shaken Bouffier recalled that Schaefer, who was Hesse's finance chief for 10 years, had been working "day and night" to help companies and workers deal with the economic impact of the pandemic.

"Today we have to assume that he was deeply worried," said Bouffier, a close ally of Chancellor Angela Merkel.

"It's precisely during this difficult time that we would have needed someone like him," he added.

Popular and well-respected, Schaefer had long been touted as a possible successor to Bouffier.     

Like Bouffier, Schaefer belonged to Merkel's centre-right CDU party.

He leaves behind a wife and two children.