I was just listening to this podcast. She says that the famine in Ukraine, caused by the Soviet Union, was kept a secret by the regime, so the rest of the world didn't know about it.
However, she also said that, in the USSR, it was generally well known but foreign journalists were not allowed to write about it (she mentioned for instance the NYT foreign correspondent).
What I'm wondering is: why didn't the journalists try anyway? People were still moving in and out of the country so they could have slipped a notebook or something for their home newspaper? Was it really that hard to get any information out of the country?
Some actually did. The infamous "Russians hungry, but not starving" article in NYT was written as a response to the articles of Gareth Jones. Jones only ruined his career with his attempt to shed light on Holodomor and was shot in (most likely) NKVD arranged "bandit kidnnaping" in 1935
You can find most of Gareth Jones literally legacy in website dedicated to him (terribly designed as it is) and also I really recommend to watch Sergej Bukovskij's The Living, were Jones diaries intersected with interviewing the survivors and diplomatic reports from the period. It's a bit on the artsy side with all the long silent shots of scenery and "behind the scenes" material, but still one of the best Holodomor documentaries that is.