Journalists Lisa Ling and Laura Ling were on CNN’s “Reliable Sources” yesterday, and spoke to Howard Kurtz about the media strategy behind the effort to free Laura and her Current TV colleague Euna Lee from a North Korean prison cell.

Among the revelations was that Lisa, upon learning of her sisters arrest, lobbied cable news executives, producers and correspondents to limit coverage of the story. The fear was that it could upset the unpredictable leadership in the totalitarian state, and could put her sister in jeopardy.

Upon finding out that North Korean leaders may have had access to CNN, they changed their strategy, making an effort to appeal directly to the North Korean government on the channel.

Lisa Ling told Kurtz:

CNN was vital, CNN we believe is the only American news channel the North Koreans see. doing an hour with Larry king and Anderson Cooper’s show, which aired the morning of the trial, was absolutely essential for us.

Later on, Lisa says she reached out to CNN U.S. president Jon Klein and asked him if the netwrk could televise Secretary of State Hillary Clinton’s call for amnesty “and play it as often as they could,” in an effort to send a message to the North Korean government.

The full interview is below.