Tour de France-winning cyclist Jan Ullrich was arrested Friday for allegedly assaulting a prostitute in Frankfurt, police said, just a week after the German national was briefly detained in Spain.
"He is in police custody," a German police spokesman told AFP, adding that the 44-year-old "was under the influence of alcohol and drugs".
Ullrich had allegedly called on the services of a prostitute at the five-star Villa Kennedy Hotel in Frankfurt, Bild daily reported.
But he then got into a quarrel with the "escort lady" and "physically attacked and injured her," police said.
Ullrich allegedly had "so tightly choked her that her vision went black", said prosecutor Nadja Niesen, adding that an investigation is continuing on possible "grievous bodily harm".
"The accused cannot yet be heard. He is still under the influence of significant levels of alcohol and drugs," she added.
Ullrich's latest woes came a week after he was detained for 24 hours in Spain for allegedly forcing his way into the Mallorca home of his neighbour, German actor Til Schweiger, and threatening him.
Following the incident, Ullrich said early this week he would go into rehab and seek help for his drink and drug addiction.
"I have a good feeling in my gut, I feel good. This will be my new start," Ullrich told Bild.
But he had only arrived back in Germany on Thursday evening to start his therapy before getting caught up in the latest drama, Bild reported.
Ullrich counts among a growing number of prominent sports stars who appear to have faced trouble adjusting to life after retirement.
Golfing star Tiger Woods and Argentina football great Diego Maradona are among those who have battled alcohol and drug problems.
The former cyclist's dramatic fall from grace came two decades after he became the only German to have won the Tour de France, in 1997.
Born in former communist East Germany, Ullrich racked up his triumphs after reunification, turning him into a national hero.
He later also won Olympic gold in Sydney in 2000, but failed to replicate his victory at the gruelling French race, finishing for several years behind US cyclist Lance Armstrong.
Like Armstrong, who was subsequently stripped of all his seven Tour de France wins over doping, Ullrich was embroiled in allegations that he used performance boosting substances.
The German was excluded from the 2006 Tour de France over his links to the Operation Puerto scandal that centred on disgraced doctor Eufemiano Fuentes, who gave performance-enhancing blood transfusions to top cyclists.
After retiring from cycling in 2007, Ullrich finally came clean in 2013 about his doping past.
Since then, he has been caught up in drinking problems.
In 2014, he injured two people in a car crash in Switzerland, and was charged with drink driving.
He was convicted three years later over the case by a Swiss court. Sentenced to 21 months in prison, Ullrich was able to convert that into a suspended sentence of four years plus a fine of 10,000 euros ($11,460).
His drink and drug habit led to his separation from his wife Sara at the end of 2017, media reported, noting that she has since moved with their three sons to the Allgaeu region of southern Germany.
Ullrich has a 15-year-old daughter from a previous relationship, with Gaby Weiss.
Going into rehab had been a condition for him to be able to see his children again, Ullrich had said.
Amid his latest woes, his former rival turned friend Armstrong offered his support earlier this week, according to Bild.
Ullrich's lawyer Wolfgang Hoppe told the newspaper that Armstrong said he was "ready to immediately get into a plane with his doctor and come to Europe" to help the German.
Armstrong "said that the cycling community must hold together. But that what's most important is that Jan first allows himself to be helped," said Hoppe, recounting a telephone conversation with the disgraced US cyclist.