Moscow (CNN) "Why does Russia never leak?" I asked the investigative journalist sitting opposite me in a dingy Moscow café.

He took gulp of espresso coffee, then after realizing I wasn't joking, he told me.

"Because they kill you, of course," he said.

It was a point well made in a country where journalists , campaigners and even opposition figures have met sticky ends.

For my contact, it was that risk of retribution that accounted for the drought of information in Russia about contacts between the Trump campaign or administration officials and the Kremlin.