"She is not in rehab," the rep told Us Weekly magazine, rubbishing reports that appeared in two US tabloids this week claiming that Nicole had suffered a relapse.

"She is at home in Glendale. Sobriety is an ongoing process but she is sober," added the rep who confirmed that that Nicole still visits a rehabilitation centre on a regular basis to see her therapist.

The 25-year-old was charged with a DUI in December after being pulled over for driving the wrong way down a California highway, for which she’s due in court on June 8 for a pre-trial hearing.

She received three years probation for a DUI conviction in 2002 and had her driving license suspended for one year. Nicole was then arrested just six months later for possession of heroin and driving with a suspended license.

After entering a drug-diversion program, she cited her parents’ divorce as contributing to her downward spiral.

"I was like a trash can - I took everything," she told Oprah Winfrey Show, adding: "I was definitely trying to mask hurt, abandonment. I had no idea I was feeling this way."

Nicole diagnosed with medical condition - Mare 22 2007
Nicole Richie has been diagnosed with hypoglycaemia, it has been announced.

A rep for The Simple Life star - who has struggled with health issues - has acknowledged that a recent hospital visit was as a result of the condition, which is otherwise known as low blood sugar.

"In her ongoing effort to focus on her well-being, Nicole has recently been diagnosed with hypoglycaemia," her spokesperson tells People magazine.

Nicole, who was apparently shooting her TV show when she visited the hospital, certainly appears to have the symptoms associated with the illness, according to the mag. It reports that the 25-year-old has been feeling faint and has to go and lie down in her trailer, often for "a good part of the day".

The rep added: "[She] is taking steps to manage it."

The news comes as the star’s reality TV show gears up for its fifth season. Ironically, Nicole and best friend Paris Hilton work as counsellors at a health camp.

Nicole suffers on set - Mar 6 2007
Nicole Richie headed to hospital last Friday, after suffering from dehydration on the set of her reality show The Simple Life.

The 25-year-old has notoriously struggled with her health and was looked at by a doctor on set, before being shipped to hospital.

She was put on an intravenous fluids drip for fifteen minutes before being released and sent home where she has been recuperating, according to her spokesman.

Her rep released a statement regarding the incident, saying: "Nicole is home resting and will return to work this evening. We are proud of the weight that Nicole is gaining and her focus on her health."

The new series of The Simple Life will feature Nicole and her co-star Paris Hilton moonlighting as counsellors at a kids’ camp. The pair had one season as sworn enemies in which they never saw each other.

They have since reconciled and are once again best friends.

Nicole Richie on drink-drive charge - Feb 16 2007
The Simple Life star Nicole Richie has been charged with driving under the influence after her car was reported driving in the wrong direction on a motorway.

Richie was arrested on December 11 last year after she failed a sobriety test, according to the California Highway Patrol (CHP).

The case contains an allegation that Richie, 25, has a prior conviction, the Los Angeles County district attorney’s office said.