Prince Philip leaves London hospital

Prince Philip, Queen Elizabeth II's husband, left a London hospital on Tuesday following "observation and treatment."

He spent four nights in the King Edward VII's Hospital in central London for what Buckingham Palace earlier said was "in relation to a pre-existing condition., Deutsche press agency (dpa) reported.

Philip was seen sitting in the front passenger seat of the car that took him from the hospital.

The 98-year-old was expected to travel to the royal Sandringham estate in Norfolk, eastern England, to spend Christmas with the queen and their family.

The British royal family exchange gifts on Christmas Eve and have a formal dinner.

Philip, whose official title is the duke of Edinburgh, has spent much of his time at the estate since retiring from most public duties in May 2017.

He was admitted to hospital on Friday.

The move was labelled "a precautionary measure, on the advice of His Royal Highness' Doctor," the palace said.

It is not publicly known what he was treated for.