An IT worker from Watford received thousands of abusive tweets after he was mistaken for an Olympian who accused a rival of doping.

Mark Horton was targeted after swimmer Mack Horton, who won gold in the 400m freestyle in Rio on Saturday, said second-place Sun Yang, was a drugs cheat.

The Australian swimmer's Twitter account was bombarded with angry messages - as was the account of Mark, a website designer from Longspring in Watford.

Mark, 36, said: "When I woke up on Sunday I was completely bamboozled. After a quick search I found out who Marc was and what had happened. It made my weekend rather interesting.

"It started off quite funny but then the abuse got worse. All of a sudden it escalated. Luckily, I don't speak mandarin."

Mark said he woke up on Sunday morning to thousands of people calling on him to apologise.

When asked if he had considered changing his Twitter handle, Mark told the Observer: "I could have changed my name but I was quite enjoying the reaction.

"It is obviously a mistake, it's a bonkers case of mistaken identity.

"I have been on Twitter for 10 years and noting like this has happened before. My phone hasn't stopped all day.

"My friends and family think its hilarious."

Mark was targeted relentlessly by trolls who accused him of being a 'coward' and a 'sinister villain'.

"For the record I'm not the Australian swimmer who said something about a Chinese swimmer #sunyang", the Clarendon Road worker tweeted after hours of abuse.

"Not only a liar and a loser in life but also a coward who doesn't have the guts to admit what he say (sic)," user @summeratjuly posted, followed by a series of poo emojis.

"Sun is a good athlete! AND he is not a drug cheater. So you should apologise to him", Jessica wrote.

When the trolling failed to stop, Mark said he was forced to send out a second message to those wrongly accusing him of being an Olympic athlete, this time appealing to Mack himself.

Mark added: "It feels weird. It is like I am a celebrity in some way but people have no idea who I am.

"The funniest thing now is I am getting hundreds of tweets from Chinese people apologising for the mistake. Last time I looked I had 200,000 mentions in 36 hours."

Horton has refused to back down from his comments, which the Australian Olympic Committee have supported.

The bitter rivalry between Horton and Sun Yang has set the stage for what will no doubt be an explosive clash when the pair go head-to-head in the 1500 metres this weekend.