We saw the column of military vehicles approaching along the highway as we were driving back to the small truckers’ motel in which we were staying. There had been other convoys like it on the road during the day, but this one was intriguing. It was getting dark, and it was heading towards the border with Ukraine. As we drove past, I counted 23 armored personnel carriers (APCs), as well as a number of fuel trucks and other support vehicles — all marked with black Russian military plates.

I was with Roland Oliphant of the London Daily Telegraph and we had already filed our stories for the day. But I suggested we turn round and follow, to see where this column was going. It was the start of a journey deep into Russian disinformation.

It was the summer of 2014 and we were in southern Russia, not far from the city of Rostov-on-Don. We had come to follow another convoy, which Moscow said was a “humanitarian” mission of trucks carrying aid to the separatist republics inside Ukraine. But given widespread reports that the Kremlin was also funnelling weapons to the separatists, there was much suspicion about what exactly was in these trucks. My newspaper, The Guardian, had dispatched me from Moscow to find out more about the convoy as it moved towards eastern Ukraine “Wow, they’ve gone into Ukraine,” said the driver, under his breath

The trucks had stopped short that day. So we had driven up to the actual border post at Izvarino to look around and then spent a couple of hours in the nearby town of Donetsk — not to be confused with the separatist capital inside Ukraine — before deciding to head back to our motel. And it was just after leaving the town that we encountered the Russian APCs and fuel trucks.