Scotland was noted for his work during and after World War II as commandant of London Cage, an MI19 interrogation facility that was subject to frequent allegations of torture.

[2]: 10 In his 1957 memoir The London Cage, Scotland wrote,[2]: 10 Perhaps because I had a variety of uncles, aunts and other relatives living abroad, my mind was focussed from an early age on the notion of a career overseas, and before I was twenty this compulsive travel urge was again asserting itself.He travelled to South Africa with the intent of joining the British Army, as his brother was serving there and promised to get him in his unit.

In The London Cage he says he took part in "several battles" with the Khoikhoi, then engaged in an uprising against German rulers of South West Africa.

[2]: 14 During that time, Scotland began unofficially reporting German manpower and other information to British intelligence in Cape Town "and to General Smuts' agents on their periodic visits to me in my bushland commercial headquarters.

[2]: 23  He was interned in the prison at Windhoek until 6 July 1915, when the area was captured by British Empire troops from the Union of South Africa.

[2]: 28 In the spring of 1918, Scotland made three secret trips behind German lines in Beverlo, a town in Flanders where porous security allowed transit into German-occupied Belgium.

He was appointed Officer of the Order of the British Empire (OBE) on 1 January 1919, in a group of honours awarded "for valuable services rendered in connection with military operations in France and Flanders".

[5] After the First World War, Scotland returned to South West Africa and then obtained what he describes in The London Cage as a "roving job with a famous commercial enterprise.

During one of his trips to Germany in 1937, Scotland says, he met with Adolf Hitler at a friend's house in Munich, and discussed South West Africa.

He found British forces ill-equipped to deal with war prisoners, with the staff assigned to such duties consisting of writers and journalists, some with background in security work but none with training or knowledge of military intelligence.

[2]: 63  Among the Nazi war criminals confined at the London cage was Fritz Knöchlein, who was in charge of the murder of 97 British prisoners who had surrendered at Le Paradis, France in May 1940 after protecting the evacuation from Dunkirk.

[2]: 81 In The London Cage Scotland spoke disparagingly of the varying treatment of Nazi war criminals, and the necessity of prompt prosecutions.

"[10] Scotland refused to allow Red Cross inspections at the London Cage, on the grounds that the prisoners there were neither civilians or criminals within the armed services.

Liddell said that "Scotland turned up this morning with a syringe containing some drug or other, which it was thought would induce the prisoner [Tate] to speak.

[13] At his war crimes trial, SS General Fritz Knoechlein claimed that he was tortured, which Scotland dismisses in The London Cage as a "lame allegation".

[1] Scotland said in his memoirs that Knoechlein was not interrogated at all at the London Cage because there was sufficient evidence to convict him, and he wanted "no confusing documents with the aid of which he might try to wriggle from the net."

At one stage the local police called in to enquire why such a din was emanating from sedate Kensington Palace Gardens.

"[2]: 81 At a trial in 1947 of eighteen Nazis accused in the massacre of fifty Allied prisoners who escaped from Stalag Luft III, the Germans alleged starvation, sleep deprival, "third degree" interrogation methods, and torture by electric shock.

"At more than one stage in those fifty days of courtroom wrangling, a stranger to such peculiar affairs might have suspected that the arch-criminal of them all was a British Army intelligence officer known as Colonel Alexander Scotland.

by the constant focus on our supposed shortcomings at The Cage, for it seemed to me that these manufactured tales of cruelty toward our German prisoners were fast becoming the chief item of news, while the brutal fate of those fifty RAF officers was in danger of becoming old history.

In 1955, Special Branch detectives searched his home and seized all three copies of the manuscript, as well as Scotland's notes and records, some of which were official files he had retained at the end of the war.

Further, the War Office does not in any way vouch for the accuracy of the facts and does not necessarily accept any opinions expressed in this book.In 1957, Scotland was technical advisor to the movie The Two-Headed Spy, starring Jack Hawkins as a British intelligence agent named Scotland who poses as a general of the German Wehrmacht named Schottland.

Scotland does not mention the movie in The London Cage but says that false stories of his serving on the Nazi general staff circulated in the British press after his testimony at the 1947 trial in Italy of Field Marshal Albert Kesselring.