Uber has revealed it received five rape allegations worldwide between December 2012 and August 2015.
The ride-request app company said the figure accounted for 0.0000009 percent of more than 500 million Uber journeys made during that time.
The information was released after Buzzfeed obtained screenshots suggesting more than 5000 messages concerning rape had been logged by Uber customer support.
But Uber said Buzzfeed's numbers were "highly misleading".
Screenshots published by Buzzfeed showed a support centre agent searching Uber's customer correspondence database for terms such as "sexually assaulted" and "rape".
There were more than 5800 search results for "rape" and 6100 for "sexual assault", with some emails showing descriptions such as "Driver sexually assaulted me".
In a blog post, Uber said the numbers had been overstated for a variety of reasons:
The results also included questions about sexual assault from customers who had seen the topic raised in news reports.
The ride-sharing company said an analysis of its search results showed five conversations that alleged rape had occurred during December 2012 to August 2015.
It said 170 messages included a "legitimate claim of sexual assault".
'Resolve without escalating'
Uber added: "When serious incidents occur, people often report them directly to law enforcement. Therefore, those incidents may not be reflected in the numbers."
Buzzfeed asked Uber to provide the data for independent analysis, but Uber responded that this would be a "serious breach of our riders' and drivers' privacy".
Details of Uber's instructions for support centre staff were also among the leaked screenshots.
Instructions for dealing with drivers reported for drinking or taking drugs state: "If rider does not want to escalate with [law enforcement] or media, follow strike system, issue warning and resolve without escalating."
Writing on Medium, Uber said: "We're the first to admit that we haven't always gotten things right. But we are working hard to ensure passengers everywhere can get a safe, reliable ride.
"Sadly, no means of transportation is 100 percent safe today. Accidents and incidents do happen.
"It's why we are working to build an exceptional customer support team that can handle problems when they occur, including working with law enforcement."