The relationship between Edward Snowden's family and WikiLeaks turned acrimonious as a lawyer for the whistle-blower's father suggested that the anti-secrecy organisation is standing in the way of his efforts to speak to his son, who is stranded in Russia.
Bruce Fein, a lawyer for Lonnie Snowden, said WikiLeaks founder Julian Assange called on Saturday and told him that Lonnie Snowden could talk to his son through an "intermediary".
WikiLeaks has been aiding Edward Snowden in his flight from US authorities, who have charged him with leaking classified documents about government surveillance.
"We are obviously concerned. If Julian Assange can talk to Edward directly, why can't his dad?" said Fein, who criticised what he called the "circus" of Snowden's efforts to find asylum abroad, which WikiLeaks has apparently been co-ordinating.
His comments on Tuesday, the latest sign of tensions between Snowden's father and Assange's group, came as Lonnie Snowden issued a broad defence of his son, a former National Security Agency contractor who has admitted leaking information about secret surveillance programs.
In an open letter released on Tuesday, the elder Snowden, a retired US coastguard officer, praised his son as "a modern day Paul Revere summoning the American people to confront the growing danger of tyranny and one branch government".
"What you have done and are doing has awakened congressional oversight of the intelligence community from deep slumber," said the letter.
Assange has acted as a spokesman for the confessed leaker, and a top WikiLeaks lieutenant accompanied Snowden to Moscow.
The anti-secrecy group and Snowden share similar experiences; the US government has also targeted WikiLeaks over its release of a massive cache of sensitive diplomatic and military documents.
Snowden's father, however, has indicated that he does not welcome the group's assistance to his son. In an interview on the Today show last week, Lonnie Snowden expressed concern about WikiLeaks' influence on his son.
Assange said on Sunday on ABC's This Week that "every father would be worried in this situation" and vowed to "put some of his concerns to rest".
That apparently has not happened. People close to Lonnie Snowden said on Tuesday that he remains suspicious of Assange's motives.
And while WikiLeaks has been aiding Snowden's flight, Fein last week wrote to the Justice Department and said his client was confident Edward Snowden would turn himself in to US authorities under certain conditions.
A spokesman for WikiLeaks did not return calls or e-mails seeking comment.