Queen Elizabeth's 86-year-old husband Prince Philip, famed for his forthright personality, has been taken to hospital with a chest infection, Buckingham Palace said.

A palace spokeswoman said: "The Duke of Edinburgh has been admitted to King Edward VII Hospital (in central London) for assessment and treatment for a chest infection."

The blunt-talking prince has been a pivotal figure in the House of Windsor for more than four decades, bringing acerbic wit and unflagging energy to his role in the monarchy. He was admitted to hospital yesterday afternoon. It is not known how long he will be staying in hospital, the palace said.

The spokeswoman said it was not clear whether any members of the royal family will be visiting him. All his official engagements have been cancelled for the weekend.

Prince Philip has attracting unwelcome headlines over the past six months at the inquest into the death of his former daughter-in-law Princess Diana, who died in a 1997 Paris car crash with her lover Dodi al-Fayed.

Dodi's father, luxury storeowner Mohamed al-Fayed, alleges that his son and Diana were killed by British security services on the orders of Prince Philip.

Fayed believes her killing was ordered because the royal family did not want the mother of the future king having a child with his son. He alleges that Diana's body was embalmed to cover up evidence she was expecting a baby.

In an emotional outburst in court, al-Fayed called Prince Philip a "nazi" and a "racist."

But Lord Justice Scott Baker, presiding judge at the inquest, said there was "not a shred of evidence" to back al-Fayed's conspiracy theories.

When sending the jury out on Wednesday to consider their verdict, he specifically told them they could not decide that Dian and Dodi's deaths were a staged accident.