Sam Smith said he wanted to highlight how "ridiculous" it is to be racist in 2016 when he tweeted about a friend who was allegedly the target of abuse.
The singer, who has been nominated for the best original song Oscar for James Bond theme Writing's On The Wall, said earlier this week that he was left ''speechless'' after his friend was "verbally abused racially in London".
Some Twitter users suggested that Smith was naive to be surprised at such an incident and a few mentioned the term "white privilege".
In a statement posted on Instagram, the 23-year-old star said: "For the record, I was merely sharing an experience I had in the hope it would draw attention to how ridiculous it is to be racist in 2016.
"This is not about me in any way, it's about a deep rooted issue we have in our society that should now be extinct.
"I don't profess to know or remotely understand what it means to be on the receiving end of racist abuse, but having been bullied my whole life for being gay, what I do know is that it is wrong and completely unacceptable.
"Here's to people being allowed to be people."
It is unclear what exactly happened and Smith does not refer to a precise time or location in his series of tweets.
He wrote: "Just experienced my friend getting verbally abused racially in London. I am absolutely SPEECHLESS.
"I never ever ever ever thought that would happen here. Absolutely speechless and hurt.
"I feel like I have to shine some sort of light on it. The police were so unhelpful in the situation and its deeply shocked me.
" Humans are HUMANS.
"I feel like I have to say something. I'm just so upset. So UPSET.''
A spokesman for the Metropolitan Police said they were ''aware'' of the tweets, but were unable to comment further.