BERLIN — On Wednesday, German Interior Minister Thomas de Maiziere defended a leaked government report alleging Turkey was a hub for Islamist groups, a charge that has further strained tensions with Ankara, a key partner in efforts to stem mass migration.

Turkey and Germany have had a series of disputes in recent months, just as the European Union has been trying to secure Turkey’s help in tackling the influx of migrants to Europe, of which Germany has taken in the bulk.

Ankara has also been incensed by criticism from the West of its crackdown following a failed coup attempt on July 15.

The government report, disclosed by German public broadcaster ARD this week, said Turkey had become a hub for Islamist groups and that President Tayyip Erdogan had an “ideological affinity” to Hamas in Gaza, the Muslim Brotherhood in Egypt and groups of armed Islamist opposition in Syria.

De Maiziere told German regional broadcaster rbb: “There’s nothing to regret” when asked if he regretted the paper. He said the report showed one aspect of Turkey, but that there were other aspects beyond that.

Earlier in the day, Interior Ministry spokesman Johannes Dimroth said the report was signed by a deputy minister and that neither de Maiziere nor the Foreign Ministry had been involved.

“Where people work, mistakes can happen,” Dimroth said.

Turkey reacted with fury to the report.

“The allegations are a new manifestation of the twisted mentality, which for some time, has been trying to wear down our country by targeting our president and government,” the Foreign Ministry said in a statement.

Earlier this year, Erdogan reacted angrily to the broadcast of a satirical song about him on German television and launched legal action against the comedian who wrote it.