The letter was posted on the website of the Internet newspaper "Ukrayinska pravda."
On 25 July, "Ukrayinska pravda"reporter Serhiy Leshchenko asked Yushchenko to comment on reports that his son Andriy drives a car and uses a cell phone that reportedly cost more than 100,000 euros and 4,000 euros, respectively.
Yushchenko said that his 19-year-old son has a job that allows him to rent the car and that the phone was a present from a friend.
When the reporter asked where his son worked, Yushchenko said: "Act like a polite journalist and not like a hired killer."
In their letter, journalists say the incident is the latest sign of a worrying trend among Ukraine's authorities, who they say "disregard" freedom of the press.
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