A postmortem suggested that Miss Dykes had been been strangled with a rope and police sources told the Telegraph she had been sexually assaulted.
Mr Houchiye was arrested last week at his apartment, according to security sources.
Uber confirmed the man was a driver with the company, that he had been working for them for two months and had passed criminal background checks.
Miss Dykes, from London, had been out at a bar on Friday night for a British embassy colleague’s farewell party in the central Gemmayzeh neighbourhood of the city.
She left before midnight, telling friends she had an early flight home to catch for Christmas.
CCTV footage taken from near the bar showed Miss Dykes getting into a black 4×4-style car.
The suspect, who has served time in prison for drug offenses, picked her up from Gemmayzeh and then drove to the nearby Achrafiyieh neighborhood where she lived, but did not drop her there.
She had booked the ride using the app, whose driver identification and rating system is seen by many in Lebanon to make it safer than hailing a cab off the street.
The driver "tried to rape her and when she resisted he strangled her… took her wallet and threw her in a dumpster," according to a security official.
Police traced the suspect’s licence plate through surveillance cameras on the highway, where Miss Dykes’ body was dumped around 4am.
A spokesman for Uber said: "We are horrified by this senseless act of violence. Our hearts are with the victim and her family. We are working with authorities to assist their investigation in any way we can."
Miss Dykes had been working in Beirut as the programme and policy manager for the Department for International Development since January 2017.
The daughter of author Jane and lawyer Philip who moved to Hong Kong two years before her birth, Miss Dykes had worked for the Foreign and Commonwealth Office since 2010, previously with a focus on Libya and Iraq.
She boarded at public school Malvern St James Girls School in Worcestershire before later studying anthropology at Manchester University and International Security and Global Governance at Birkbeck, University of London.