A former English National Ballet principal dancer has been told he faces a lengthy jail term after he was found guilty of sexually assaulting young female students.

Yat-Sen Chang, 49, was convicted at Isleworth Crown Court of 12 counts of sexual assault and one count of assault by penetration, a court official said.

The offences took place at the English National Ballet and Young Dancers Academy in London between December 2009 and March 2016, and relate to four female complainants who were aged between 16 and 18 at the time.

They accused Chang of touching them inappropriately during massages at the schools.

The jury convicted Chang, who lives in the German port city of Kiel, after 13 hours and one minute of deliberations.

He was remanded in custody to be sentenced at the same court on June 18.

Judge Edward Connell told Chang his offending “escalated in seriousness” and warned him he faces a “lengthy custodial sentence”.

Opening the trial last month, prosecutor Joel Smith said the “internationally renowned” ballet dancer was “both famous and revered” by young dancers and students of ballet.

Mr Smith told jurors Chang “used his position” to commit sexual offences against young students in his care, adding: “Children, whom he had been trusted to teach.

“For his part, he trusted that his fame and his position would protect him from complaint, or from consequences of his actions.

“The story of this case is sadly often heard – it is a man with power and prestige using them to abuse younger women.”

Nahid Mannan, a senior crown prosecutor in the Crown Prosecution service, said: “Yat-Sen Chang used his position as a famed and trusted ballet teacher to groom and sexually assault teenage dancers under his training.

“At 20 years their senior, Chang would have been well aware that his conduct was grossly inappropriate and predatory.

“Yet he used his power and influence to abuse and sexually intimidate his young victims.

“During the trial Chang claimed that although he had advised students to get massages or do stretches to help with tight calves, he had never offered to personally massage them.

“In fact, he said he had only touched students to correct their posture during lessons.

“However, the strong prosecution case which included evidence provided by the victims in pre-recorded video interviews, meant that the jury were able to convict Chang for his crimes.

“I would like to highlight the courage of the young victims in this case without whose testimony this result may not have been possible.

“Sexual crimes are some of the most serious and complex cases to prosecute – the CPS will always aim to bring these cases to court where there is the evidence to do so.”

Chang was on trial for 14 offences in total, and was found not guilty of one count of assault by penetration.

During the trial Chang said he had “no idea” why the allegations were made against him, and said he had not touched any of the complainants in an inappropriate or sexual way.

According to a profile on the German Theatre Kiel website, the Cuban dancer joined the English National Ballet in 1993 and was a principal dancer until 2011, where he performed in productions which included The Nutcracker, Coppelia and Sleeping Beauty.