Noah Becker, son of the German tennis star Boris Becker, plans to press charges against a deputy from a far-right party who called him a “little half-negro” on Twitter, the Bild newspaper has reported.

The 23-year-old, whose mother, Barbara Becker, is the daughter of an African American man and a German woman, took the decision in consultation with his father.

“I have been retained to quickly take the necessary steps under criminal and civil law against MP Jens Maier on the basis of this clearly racist tweet,” the Becker family lawyer Christian-Oliver Moser told Bild.

Maier, a former judge who was one of nearly 100 members of the Alternative für Deutschland (AfD) party elected to parliament in the September election, had attacked Noah Becker over an interview in which he complained about being seen as the “eternal son” of his famous father.

“It seems the little half-negro simply got too little attention – that’s the only explanation for his behaviour,” said the tweet posted from Maier’s account on Tuesday.

It has since been deleted and Maier told Bild that one of his staff members had written it. It was the second time in a week that AfD deputies had stirred outrage on social media.

On Tuesday German police filed a complaint against Beatrix von Storch, deputy leader of the party’s parliamentary group, over a tweet on New Year’s Eve which they say violated laws against incitement to hate.

Von Storch had criticised Cologne police for sending a new year’s greeting in Arabic on Twitter.

“What the hell is going on with this country? Why is an official police site — tweeting in Arabic?” she wrote. “Did you mean to placate the barbaric, Muslim, gang-raping hordes of men?”