LONDON -- No single error led to the capture of 15 sailors and marines by Iran in March, Britain's defense chief said Tuesday, but he acknowledged the Defense Ministry was wrong to let them sell their stories to the media after their release.

There was no case for disciplinary action as a result of the seizure, said Defense Secretary Des Browne.

He said an inquiry had concluded that the mariners' capture by Iran's Revolutionary Guard was not the result of "a single gross failing or individual human error." Instead, the inquiry found the seizure resulted from "the coming together of a series of vulnerabilities," he said.

Browne presented the findings to British lawmakers Tuesday, but the full report by retired Lt. Gen. Sir Rob Fulton will not be released because it is classified and contains tactical military information.

"The central lesson is that we must improve our ability to identify and assess the risks that this complex environment generates, and to train and posture our forces accordingly," Browne told lawmakers.

Adm. Jonathon Band, the head of the Royal Navy, said many of the inquiry's recommendations were already being implemented. "The navy is keen to repair any dent as quickly as possible," he said. "We will recover from this. I accept it was a bad day."

The inquiry recommends that specialist teams should be deployed for boarding operations, when military personnel search ships for contraband and weapons. It also suggests further training for those teams, which Browne said was already being carried out.

A second inquiry conducted by Tony Hall, the British Broadcasting Corp.'s former director of news and current affairs, slammed the Defense Ministry for allowing the seized sailors and marines to sell their stories to the media.

"The acceptance of payment from the media offended the public and their view of the special place of the armed forces in British life," Hall said. "That the decision to accept payment caused such anger and concern was entirely understandable."

Normally, serving military personnel are not allowed to take payment from media organizations. At the time, defense officials cited exceptional circumstances.

"I acknowledge this failing was my responsibility," Browne said.

Hall's inquiry recommended that media payments "to serving military or civilian personnel, for talking about their work, should simply not be allowed."

The seven sailors and eight marines were searching a merchant ship in late March when their two inflatable boats were intercepted by Iranian vessels near the disputed Shatt al-Arab waterway in the Persian Gulf, officials said.

Iran claimed the British had strayed into its territorial waters, a charge Britain denied.

During the crew's captivity, Britain accused Iran of using the group for propaganda by putting them on Iranian TV in appearances in which they "admitted" trespassing in Tehran's waters. The crew was freed nearly two weeks after their capture by Iranian President Mahmoud Ahmadinejad, who called their release a gift to Britain.

They returned home to a warm welcome -- but public feeling quickly turned frosty when it was announced the captives would be allowed to sell their stories to Britain's tabloid newspapers.

The parallel inquiries were ordered by Browne.