The Interior Ministry accused the centre of presenting itself as a purely religious organisation with no political agenda but said its probe has found the contrary to be true.

In a statement, the ministry said that it "banned the Hamburg Islamic Centre and its affiliated organisations throughout Germany to date, as it is an Islamist extremist organisation pursuing anti-constitutional objectives".

Accusing the group of being a "direct representative of Iran's supreme leader", the ministry said the centre spreads Tehran's ideology "in an aggressive and militant manner".

It is allegedly seeking to "establish authoritarian, theocratic rule" in place of a democracy, said the ministry, accusing the centre of backing the "military and political dimension" of organisations like Hezbollah.

Investigators raided 53 properties allegedly linked to the centre across Germany on Wednesday, and the ban will also be imposed on several organisations related to the Hamburg centre -- including four Shiite mosques.

"I want to make it very clear: We are not taking action against a religion," said Interior Minister Nancy Faeser.

"This ban absolutely does not apply to the peaceful practice of the Shiite religion," she stressed.

Germany considers Hezbollah a "terrorist organisation" and in 2020 banned Hezbollah from carrying out activities on its soil.

The Hamburg Islamic Centre runs the Imam Ali Mosque, also known as the Blue Mosque.

Founded by Iranian immigrants in 1953, the Hamburg Islamic Centre had already been under surveillance by domestic intelligence for some time.

In November, investigators had conducted sweeping raids of its premises and other related sites across seven of Germany's 16 states.