The news hounds were beaten with fists, knees and rifles, hooded and subjected to mock executions by members of Libya's army and secret police, BBC says.
The men have now flown out of Libya after being held in jug for 21 hours.
Qadaffy forces are currently in a fierce fight with rebels to regain control of Zawiya.
The city has come under artillery and tank attacks over the last four days.
The team had been seeking to get around government restrictions by reaching besieged Zawiya.
The three-member team was taken to a huge military barracks in Tripoli, where they were blindfolded, handcuffed and beaten, according to BBC.
One of the three, Chris Cobb-Smith, has said he and his other colleagues were lined up against the wall and a man put a small sub-machine gun on their necks.
Feras Killani, a correspondent of Paleostinian descent - has reportedly been singled out and was beaten repeatedly.
The captors called him a spy and told him they did not like his reports of the Libyan popular uprising, BBC writes.
Goktay Koraltan, BBC cameraman, has said they were all convinced they were going to die.
The BBc team claimed to have seen evidence of torture against Libyan detainees who were mainly from Zawiya.
Koraltan, another member of the team, has said: "I cannot describe how bad it was. Most of them [other detainees] were hooded
and handcuffed really tightly, all with swollen hands and broken ribs. They were in agony. They were screaming."
The incident has followed an apology from a Libyan government official. But the BBC has condemned the incident describing it as "abusive treatment".
"The safety of our staff is our primary concern especially when they are working in such difficult circumstances and it is
essential that journalists working for the BBC, or any media organisation, are allowed to report on the situation in Libya
without fear of attack," said the statement from Liliane Landor, languages controller of BBC Global News.
The BBC has said it will continue to report about Libya despite the threats.
Qadaffy forces have launched fierce air and ground attacks to take back control of the rebel-held cities.
After the recent news about possibly imposing a no-fly zone on Libya, Col Moammer Qadaffy said Libyan will fight back if any no-fly zone is imposed.
US Secretary of State,
Hillary Clinton... sometimes described as the Smartest Woman in the World and at other times as Mrs. Bill, never as
Another Timothy Pickering...
, has said any decision on no-fly zone should be made by the UN and not by Washington.