WWII Nazi spy radio seized by Northamptonshire Police to go on show in museum

A spy radio seized by Northamptonshire Police when Nazi sympathiser Gosta Caroli parachuted into the County one late afternoon exactly 85 years ago, is set to go on public display for the first time at Northampton Museum.

Caroli, who would later become a double agent codenamed ‘Summer’, was arrested by Superintendent AJ Norris and Inspector John Frost on September 6, 1940.

Northamptonshire Police had been alerted after farmhand Paddy Daly discovered a man with a briefcase laying in a ditch in old Barn Close Elms Farm on the Castle Ashby Estate. Paddy alerted farmer Cliff Beecher who contacted the police.

Caroli, a 38-year-old Swedish national, was later discovered to be a German spy whose mission it was to send radio reports to Hamburg about bomb damage to fields in Northamptonshire, Oxfordshire and Birmingham.

Theory has it that Caroli was meant to land near Yardley in Birmingham but instead ended up near Yardley Hastings in Northamptonshire.

Following his arrest, police recovered Caroli’s possessions from the ditch, which incredibly, included a tan coloured fibreboard briefcase containing a radio transmitter/receiver set, batteries, and a Morse key.

Also recovered were a parachute and a suitcase containing clothes, an identity card, a knife, charts, chocolate, biscuits, a tin of corned beef and six packets of cigarettes, along with a loaded German automatic pistol and ammunition, 200 one-pound notes, and a book of Red Cross stamps.

Caroli was taken to Angel Lane Police Station, Northampton, before being driven under armed guard the following morning to Cannon Row Police Station, London, and handed over to MI5 officers.

During lengthy interrogations by MI5, Caroli divulged information about his training, fellow spies, frequencies, transmission times, codes, and how to encipher messages.

To evade a civil trial and the death sentence, he agreed to enrol in the MI5 Double Cross programme under codename Summer, later transmitting misinformation to the nazis in Germany and helping the Allied Forces in the D-Day Landings.

In January 1941, Caroli tried unsuccessfully to escape. While detained in a safehouse in Cambridgeshire, he overpowered his guard, tying him up and emptying his pockets. He fled on the guard’s motorcycle, but after crashing several times and realising his escape was futile, he gave himself up to the police.  

He was immediately removed from the programme and detained until the end of the war when he was repatriated to Sweden. Caroli died in 1975.

His radio, which remains in very good condition, forms part of the Northamptonshire Police Museum collection. De-classified top-secret files relating to this case are held in the National Archives and at the Northamptonshire Records Office.

West Northamptonshire Council is hosting the History of Northamptonshire exhibition at Northampton Museum and Art Gallery between September 20, 2025 and February 2026.

Sue Ward, part of the Heritage and Legacy team at Northamptonshire Police, has been cataloguing various historical items and artefacts relating to the Force, and made the submission to the museum.

She said: “It is great to be part of the exhibition and to be included in the 100 objects of Northamptonshire history that are being exhibited.

“The radio is an important item in our museum collection and has a really interesting back story. Remarkably, the radio is so well preserved, and this will be the first time it has been on public view. It will no doubt generate interest in how our Force played such an important role in not only Northamptonshire's history but also the history of World War II.”