Sam Smith has apologised to Dustin Lance Black for claiming he was the first openly gay star to win an Oscar.

Sam Smith

Sam Smith

The 41-year-old screenwriter-and-director took to Twitter to correct the 'Stay With Me' hitmaker after he made the claim during the acceptance speech for his Best Original Song win for the 'Spectre' theme song, 'Writing's on the Wall'.

After Dustin - who won the best original screenplay prize in 2009 for 'Milk' - called him out on his error on Twitter, Sam tweeted: "Second openly gay man to win an oscar or third or fourth or 100th, It wasn't my point. Apologies for the mix up @DLanceBlack I'll be sure to check out your films now x Belated Congrats on the Oscar x (sic)."

However, Sam didn't respond to the first part of Dustin's tweet, which warned him to stay away from his fiancé, Olympic diver Tom Daley.

Dustin wrote: "Hey @SamSmithWorld, if you have no idea who I am, it may be time to stop texting my fiancé. (sic)"

Dustin also sent him a link to a video showing him accepting his prize for the movie 'Milk'. Alongside the clip, he wrote: "Here's a start."

The screenwriter took umbrage to Sam's acceptance speech in which he said: "I read an article a few months ago by Sir Ian McKellen and he said that no openly gay man had ever won an Oscar.

"If is this case, even if it isn't the case, I want to dedicate this to the LGBT community all around the world. I stand here tonight as a proud gay man and I hope we can all stand as equals one day."