UK police have arrested a man over malicious Twitter postings directed at British Olympic diver Tom Daley, whose father died of brain cancer a year ago.

After Daley finished fourth on Monday, out of medal contention at the London 2012 Olympics, a Twitter user sent him several negative messages.

Daley retweeted one of them that said: "You let your dad down, I hope you know that," according to ESPN.

Daley, 18, and diving partner Pete Waterfield had been leading the 10-meter synchronized event after three rounds, ESPN wrote.

However, a messy fourth dive saw them miss out on a medal, for which Waterfield later apologized.

According to The Sun, Daley was "gutted" after failing to win a medal in memory of his dad, Rob, who was 40 when he died.

The Twitter user, Rileyy69, taunted him by saying: “You let your dad down, you let our country down.”

He went even further later, threatening: "@TomDaley1994 i’m going to find you and i’m going to drown you in the pool you cocky t*** your a nobody people like you make me sick."

Daley, the BBC reported, responded to the harassment by posting: "After giving it my all…you get idiot's sending me this…" 

Dorset police said they had arrested a 17-year-old at a guest house in Weymouth connected to the menacing tweets, which according to the Associated Press can lead to prosecution in the UK.

The Sun a police spokeswoman as saying: "A 17-year-old man was arrested by Dorset Police officers in the early hours this morning at a guesthouse in the Weymouth area on suspicion of malicious communications. He is currently helping police with their inquiries."

Rileyy69 eventually posted a tweet apologizing for his comments, but his Twitter account was suspended overnight.

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