She's pictured out drinking and partying on most nights, regardless of where in the world she is. But now new claims have emerged that Rihanna's friends are so concerned about her welfare due to her 'excessive partying' that they are urging her to check into a rehab centre.

According to reports, Rihanna's manager and close friend Jay-Z has ordered the 24-year-old singer to seek help before it's too late.

The claims about Rihanna's wellbeing came as the singer was pictured stepping out in New York looking tired and dishevelled in possibly her most revealing outfit yet.

Rihanna was pictured wearing a tiny pink lace bandeau bra with a pleated skirt as she headed out and about in Manhattan, covering up with a white cardigan over the top at points during the outing.

She teamed the outfits with a pair of high-top trainers and sunglasses. Rihanna has sparked concern among friends and family with her love of drinking and partying, with Jay-Z apparently even threatening to drop her from his label if she doesn't get her life in order.

Things went from bad to worse when Rihanna was forced to cancel a scheduled work trip to the UK last week, after allegedly missing her flight.

A source told Closer magazine: 'Rihanna has been out of control for months. She was supposed to catch a flight back to the UK last week, but she ended up missing it, which was the final straw for management. Jay-Z hit the roof when he found out, and told Rihanna, "Go to rehab now or I'll drop you from the label". She's not happy, but she now feels she has no choice.'

However, Rihanna denied claims that she had cancelled the UK trip due to illness, insisting she just needed to spend more time with her family, particularly her grandmother Dolly who is suffering from cancer.

Rihanna first sparked concerns about her health last month when she was hospitalised for exhaustion and dehydration. The singer tweeted a picture from inside the hospital, showing her hooked up to an intravenous drip, yet weeks later she was seen out partying again.