Two men who raped and killed a Vietnamese student in the United Kingdom have been convicted of her murder.

Nguyen Ngoc Quyen. Photo PA

The pair held Nguyen Ngoc Quyen hostage for four hours in August last year, during which she was sexually assaulted and raped to a point at which they rendered her unconscious.

Her killers then drove her body to some nearby farm land, dumped the vehicle in a field and then set it on fire as 28-year-old mother of two Quyen lay slumped on the back seat. 

Yesterday after their conviction, it was revealed killers Stephen Unwin, 40, and William John McFall, 51 had both murdered before, and had been released from life sentences after spending just 13 years in prison.

Killers Stephen Unwin, 40, and William John McFall, 51 who were found guilty on Tuesday of murder of Nguyen Ngoc Quyen. Photo Northumbria Police

Speaking after the court case, Quyen’s sister, Nguyen Ngoc Quynh said: "Quyen was a loving caring mother and a simply beautiful daughter, sister and aunt who loved nothing more than spending time with her family.

"She had many friends both Vietnam and in the UK. My sister has two beautiful young children whose lives have been changed forever, they will never see there mummy again."

Quyen was in the UK studying business at the London School of Commerce. She moved to the UK in 2010. 

VNS