BERLIN -- Former Tour de France champion Jan Ullrich has been arrested and is in police custody for allegedly attacking an escort in a Frankfurt hotel.

Police spokesperson Carina Lerch says the retired German cyclist was arrested early Friday morning after police were called to the hotel. She says Ullrich was under the influence of drugs and alcohol and could be charged with "assault or attempted murder."

Lerch says "it seems Mr. Ullrich and an escort women had a dispute and that he attacked her. She alerted the hotel staff and they called police. Mr. Ullrich is still in custody."

A police statement said the woman needed medical treatment.

Ullrich won the Tour in 1997 but later admitted to doping during his career.