Turkey has condemned Germany’s summoning of its ambassador and called in Berlin’s ambassador to Ankara in a tit-for-tat move amid a row over the jailing of a Turkish philanthropist for life.

Osman Kavala was sentenced on Monday after being convicted of trying to overthrow the government by financing protests, in a case that Europe’s top court and Western powers say is politically motivated.

Media reports cited a spokesman for Germany’s foreign ministry as saying the Turkish ambassador was summoned on Friday over the sentencing of Kavala who had already been detained without conviction for four-and-a-half years.

Turkish Justice Minister Bekir Bozdag said on Twitter that Germany had trampled on justice many times in the past and said it should act in line with international law.

Germany’s ambassador to Ankara, Jurdgen Schulz, was also summoned to the Turkish Foreign Ministry on Friday, Turkish diplomatic sources said, adding he was told Ankara rejected attempts to interfere in its judiciary or politics.

“Ambassador Schulz was told that we condemn the summoning of our ambassador in Berlin over a case in our country, in a manner violating diplomatic norms, and the politicisation of the case in question,” the sources said.

Schulz, who was summoned by Turkish Deputy Foreign Minister Faruk Kaymakci, was also told that “the sentencing ruling by the independent Turkish judiciary cannot be questioned” and he was “reminded of the principle of not meddling in internal affair”, the sources added.

Critics and opposition parties say Turkish courts are under the influence of President Recep Tayyip Erdogan and his AK Party. The government denies the claims.

The Council of Europe rights watchdog this year referred Kavala’s case to the European Court of Human Rights to determine whether Turkey has failed to meet its obligation to implement a previous ECHR judgement, more than two years ago, to immediately release him.

Last October, Erdogan threatened to expel the ambassadors of 10 countries, including the United States, Germany and France, after they echoed the ECHR ruling.

The ECHR is the best-known body of the Council of Europe from which Turkey could now be suspended due to Kavala’s continued imprisonment.