Britney Spears shaved her head last week

The reports are "absolutely untrue" and "disappointing... as Britney tries to get better", Larry Rudolph told US entertainment news show Extra.

Newspapers published photographs on Saturday apparently showing the star attacking a car with an umbrella.

An earlier court hearing involving Spears and her estranged husband was cancelled after she entered rehab.

About the suicide watch claims, Mr Rudolph said: "She is in rehab, and it is very disappointing that various media outlets are running these false stories about her, as Britney tries to get better."

A lawyer for Spears' husband Kevin Federline cancelled the emergency hearing in a Los Angeles family court that had been due to take place on Thursday.

It is not known what the court hearing was about, but the former couple are in dispute over custody of their children.

Spears had entered the Promises treatment centre in Malibu the previous evening, according to Mr Rudolph.

Rehab reports

Spears, 25, has two children with Federline - five-month-old Jayden James and Sean Preston, aged 17 months.

The couple currently have joint custody under a temporary court order.

Kevin Federline was married to Britney Spears for two years

Spears reportedly sought treatment at a rehabilitation centre in the Caribbean last week but left after just one day.

US media then reported she had gone into the Promises centre, leaving a few hours later.