The organisers of Britain's Wireless Festival have rushed to deny reportssuggesting Rihanna has pulled out of the Hyde Park, London spectacular.

Nonsense! I'm not sick! I pushed my trip to London back to go spend time with my family! Sorry kiddos

The singer, who is set to headline the last night of the weekend event in July (12), pulled out of a planned trip to Britain earlier this week (beg04Jun12) to spend time with her family - and the decision has promptedbloggers and tabloids alike to speculate about the delay.

Some sources claim Rihanna is seriously ill, while others suggest she'sabout to axe a 10-week stay in London, where she was scheduled to host areality TV fashion contest throughout the summer (12).

The singer responded angrily to the false reports via Twitter.com on Thursday (07Jun12), taking aim at a U.K. tabloid for suggesting she was scrapping her British commitments.

She wrote, "Nonsense! I'm not sick! I pushed my trip to London back to go spend time with my family! Sorry kiddos. "The Sun Newspaper is like a f**kin a** hair, full of s**t!!!!!!" Any now Wireless Festival bosses have taken issue with the story, stating, "She (Rihanna) is still scheduled to perform at Barclaycard Wireless Festival". Rihanna, who is also scheduled to perform at BBC Radio 1's Big Weekend in Hackney, east London, will headline the Wireless Festival alongside Deadmau5 and Drake.