The summons relates to Mr Morton's lesser-known work, Moi - The Making of an African Statesman, a hagiography of Kenya's autocratic President Daniel arap Moi. The book was published last year to less than favourable reviews.
Mr Morton was attacked by British commentators for "airbrushing" President Moi's human rights record. In the book Mr Morton attacked "cynics [who] suggested that I had taken the Kenyan shilling simply to burnish his image" after suggestions that he was paid to write it by the President.
The author is being sued by Justice Richard Kwach for insinuating the judge was bribed and manipulated by a Moi supporter when leading an enquiry into the death of a senior Kenyan politician, Dr Robert Ouko. The judge revealed his intention to sue earlier this year.
An advertisement in the Kenyan press by Justice Kwach's solicitors gives the author's address in north London and says a copy of the summons and the complaint may be obtained from the Nairobi Central Law Courts.
Mr Morton is away and had not been told of the summons. His publisher, Michael O'Mara refused to comment.
The judge says a chapter in the book, titled "The Strange Death of Bob Ouko", implies he is corrupt and dishonest and therefore unfit to hold public office. Justice Kwach is seeking an unspecified amount in damages.
With two other judges Justice Kwach was appointed by President Moi in 1990 to investigate the death of Dr Ouko, the foreign minister. The book says the judges were frequent guests at the home of a senior Moi aide, Hezekiah Oyugi. Mr Oyugi has since died, but once threatened to name the "big men" behind the foreign minister's death.
Despite the coverage of the Ouko case, the book was very much an authorised biography written with the full co-operation of the President. In the book, Mr Morton describes as "ill-disguised racism and colonial arrogance" the criticism from the West of Mr Moi's political rule. He also defends him against international criticism over for the hundreds of deaths in the Rift Valley where Mr Moi was accused of ethnic cleansing in 1992.
Throughout the book Mr Morton uses the phrase "placed in detention" to describe the hundreds of arrests without trial and tortures which have taken place under Mr Moi's regime.Reuse content