One of Cuba's most prominent political prisoners, Dr Oscar Biscet, has been released from prison after nearly three years.

Prison officials said the 41-year-old medical doctor was let out of a high security jail in the eastern province of Holguin at 0530 (1030 GMT) on Thursday.

He was arrested in November 1999 for a series of offences, including flying the Cuban flag upside down at a news conference to protest at the lack of political freedom under Fidel Castro's one-party socialist system.

Only Dr Biscet's wife was there to meet him as he left jail several hours earlier than planned, in an apparent attempt by the authorities to minimise publicity.

After his arrest in 1999 Dr Biscet was charged with insulting a national symbol, together with public order and criminal incitement offences.

'Counter-revolutionaries'

The Cuban Government denies that there are any political prisoners on the island. It says prison inmates are there because they are common criminals and it labels dissidents as "counter-revolutionaries".

Castro denies holding political prisoners

But local human rights groups say 320 people are currently in jail in Cuba, solely because of their beliefs.

According to Dr Biscet's wife Elsa Morrejon, quoted by Reuters news agency, he suffered a serious gum infection in prison that caused three molars to fall out. She said he refused treatment because he did not trust the medical staff at the prison.

In 1999, Dr Biscet went on a 40-day water-only fast to demand the release of political prisoners in Cuba.

The Cuban Commission for Human Rights and National Reconciliation says Cuba is one of the few countries in the world that prevents the International Red Cross and other humanitarian organisations from visiting its prisons.