Details of a UK operation to rebel-held Benghazi in Libya in which eight men - six reportedly SAS - were detained, have been disclosed to the BBC.
The BBC's Jon Leyne said witnesses saw six men in black overalls land in a helicopter near the city on Friday.
They were later seized when it was discovered they were carrying weapons.
State TV has played a tape where a man said to be the UK ambassador tells a rebel spokesman the team went to liaise with rebels on the National Council.
He carries on to say the group wanted to keep an eye on the humanitarian situation in Benghazi.
Defence Secretary Liam Fox said a small diplomatic team was in Benghazi and "they were in touch with them".
The BBC's security correspondent Gordon Corera says the SAS was believed to have been in Libya protecting diplomats rather than on a military mission.
The Sunday Times reported earlier that the unit was trying to put UK diplomats in touch with rebels trying to topple the Gaddafi regime.
In a statement, the MoD said: "We neither confirm nor deny the story and we do not comment on the special forces."
Jon Leyne, who is in Benghazi, said the men went to the compound of an agricultural company where they were challenged by Libyan guards and asked if they had weapons.
"Witnesses said that when the men's bags were checked they were found to contain arms, ammunition, explosives, maps and passports from at least four different nationalities.
"The witnesses said at that point all eight men were arrested and taken to an army base in Benghazi where they are being held by the opposition forces who control this area."