Allowing British sailors to sell their stories about their capture by Iran was a "significant mistake", Foreign Office minister Lord Triesman has said.
Faye Turney has reportedly struck a deal worth more than £100,000
He was giving evidence to the Commons foreign affairs committee about the diplomatic efforts to free the sailors who were seized in the Gulf in March.
He said any future negotiations could be prejudiced by "unhelpful" conduct from the past.
The sale of stories by two of the 15 sailors prompted a political row.
The 15 sailors had initially been told they could sell their stories to the media.
The decision was later overturned but two of the crew had already struck deals.
Arthur Batchelor, 20, the youngest of the British sailors to be held captive, told the Daily Mirror about his "nightmare" at the hands of his captors.
And Leading Seaman Faye Turney sold her story to ITV1's Tonight with Trevor Macdonald and the Sun newspaper - reportedly for a six-figure sum, some of which will go to navy families.
Lord Triesman told the foreign affairs committee: "We work in a very sensitive world. These are very, very intricate and difficult discussions.
"They can easily go wrong during the course of them. And future discussions can be hopelessly prejudiced by conduct which is unhelpful from the past. '"
He said that, during the crisis, he had held discussions with the Iranian ambassador in London but had not spoken to Iran's main negotiator, the secretary of Iran's Supreme National Council, Dr Ali Larijani.
The government made contact with Dr Larijani only after he had given an interview to Channel 4 News in which he indicated he was willing to take part in discussion.