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American tennis player Tennys Sandgren has apologised for an offensive tweet he posted about a gay club in 2012.

The world number 97 lost in the Australian Open quarter-finals to South Korea’s Chung Hyeon on Wednesday.

Sandgren, who then accused the media of “demonising” and “propaganda”, deleted 18 months’ worth of tweets after being questioned about his beliefs and denying he was a far-right sympathiser.

“To everyone I offended with that, please accept my apology,” he said.

The 26-year-old was referencing a post on Twitter six years ago that said a visit to a gay club had “left his eyes bleeding”.

“I used poor and harsh words to describe a bad experience, and is not indicative of how I feel about the people in that community,” he added.

Serena Williams had earlier called for Sandgren to apologise, saying: “There is an entire group of people that deserves an apology.”