Former Panamanian leader General Manuel Noriega has failed in an attempt to secure an early release from prison in the United States.

At a parole hearing in Miami, where Noriega is serving a 30-year drug trafficking sentence, officials heard arguments for and against his conditional release.

But the petition was turned down apparently after concerns were raised about the security risk his release could pose to the former US president, George Bush.

It was Mr Bush who in 1989 ordered US forces to invade Panama, which led to Noriega's arrest.

He was brought to Florida for trial in January 1990, and subsequently convicted on drug-trafficking charges.

He was initially sentenced to 40 years in prison, but this was later reduced by a US judge to 30 years.

Routine hearing

The recent parole hearing was granted as a matter of routine, after the former leader had served 10 years of his sentence.

According to US parole guidelines, the general will now remain in prison until 2007, when he may be released if his behaviour in prison is considered to have been acceptable.

Noriega was Panama's chief of police from 1971 to 1984, when he took command of the army and, in effect, the country.

He is still wanted in Panama on charges of executing army officers in 1989, and the Panamanian authorities last year requested his extradition from the US.