The family of murdered British diplomat Rebecca Dykes have said she “wanted to make the world a better place” and they described her as “simply irreplaceable”.
The body of 30-year-old Ms Dykes, who worked at the UK embassy in Beirut was found next to a road in the east of Lebanon’s capital.
An Uber driver with “previous criminal violations” has been arrested over her murder, a senior Lebanese security source has said.
In a statement issued by the Foreign Office her family said: “For Becky to have her life cruelly taken away in these circumstances is devastating to our family.
“Becky is simply irreplaceable and we will never fully recover from this loss.”
The family said they were grateful the investigation was “moving at pace”.
They added: “Becky was genuine, generous, and loving, as anyone who knew her would agree. She was intelligent, ambitious, and dedicated to her work.
“Becky had a love of travelling, and was passionate about helping people.
“She always wanted to make the world a better place – her humanitarian work in Beirut was testament to that.”
Ms Dykes had been due to fly home to the UK for Christmas on Saturday.
The Lebanese man is said to have confessed to the killing.
Police – who say the murder was not politically motivated – are being assisted by Uber in their investigation, a spokesman for the mobile taxi firm said.
Earlier, a local forensics officer told the Associated Press news agency that Ms Dykes was strangled with a rope.
Authorities were investigating the exact cause of her death and whether she was sexually assaulted, the official said.
Lebanese media said choke marks had been found on her neck and that she had been raped. She also had a piece of string tied around her neck.
Local media reported that Ms Dykes – who had been due to fly home for Christmas – had been out in the Gemmayzeh area of Beirut on Friday night with work colleagues, and left a bar on her own at around midnight.
According to Ms Dykes’ LinkedIn profile, she had been working as a programme and policy manager for the Department for International Development (DfID) on the UK government’s Conflict, Stability and Security Fund (CSSF) programme in Lebanon.
She was a former pupil of Malvern Girls’ College and Rugby School, and had spent time at a Chinese international school.
A DfID spokesman said: “Our thoughts are with Becky’s family and friends at this very upsetting time.
“There is now a police investigation and the FCO (Foreign Office) is providing consular support to Becky’s family and working with the local authorities.”
An Uber statement said: “We are horrified by this senseless act of violence. Our hearts are with the victim and her family.”
The British ambassador to Lebanon, Hugo Shorter, tweeted his condolences saying the whole embassy was “deeply shocked” and “saddened”.
Under Lebanon’s CSSF programme, the UK Government has spent millions of pounds supporting the country’s armed forces to address “security threats originating from Syria”.
Cash has also been spent on preventing “illegal cross border activity” between Lebanon and Syria – an area where jihadists have been active – and assisting local policing.
Josie Ensore, the Daily Telegraph’s Middle East Correspondent based in Beirut, told Sky News: “It is extremely rare for any sort of foreigner to be attacked and there is very low-level crime in Beirut… I feel safer here than in London or New York, walking home or being alone.
“I think that’s why the British and American communities are very shocked about what’s happened because it really is a very rare thing to happen.”