Criminal lawyer Desmond Rosario, who formerly prosecuted cases for the Crown Prosecution Service, is wanted in connection with the attack, which is alleged to have taken place in October 2013.
The 46-year-old featured on BBC One’s Crimewatch programme on Thursday night during an appeal for information about the Sheffield incident.
The father-of-two had been due to appear for a hearing at Leicester Magistrates Court in June 2014 but failed to turn up.
A warrant was then issued for his arrest but, despite extensive enquiries, police have been unable to locate him.
Detectives said there was information to suggest Rosario could be using aliases, including the names David D’Cruz or Desmond David Luc D’Cruz.
South Yorkshire Police say that he could be looking for work as a legal professional abroad, and have reason to believe he may be travelling through Europe or Canada.
Rosario, of Sheffield, also used to represent defendants at the city’s crown court.
The barrister was a former University of Sheffield law student and helped out with teaching at the university on a casual basis but was not a member of staff.
He was married but is understood to be separated from his wife.
Rosario was featured on last night’s Crimewatch show in the Wanted Faces section of the programme — which highlights suspects being urgently sought by police.
South Yorkshire Police are appealing for anyone with information about Rosario’s whereabouts to contact them on 101.