Families of the Lockerbie bombing victims have criticised former justice secretary Kenny MacAskill for signing a deal to write a book about his decision to free Abdelbaset al-Megrahi.

Mr MacAskill was accused of cashing in after he signed a publishing deal which will see him give his account of the decision to release Megrahi on compassionate grounds.

In 2009, he released Libyan security operative Megrahi, the only man convicted of the crime, on compassionate grounds.

Megrahi served just eight years of his sentence before being freed because he was dying of cancer.

The move to write the book has been criticised by American Susan Cohen, who lost her daughter Theodora, 20, in the bombing.

She said: “I don’t care what he has to say.”

The book is the latest attempt to try to unravel why Pan Am Flight 103 crashed, killing 270 people, in December 1988.