- Police and fire crews called to BBC's central London offices at around 9am
- Security staff were seen trying to restrain man before officers arrived
- Witnesses said they saw two bottles of liquid which smelled of petrol and heard man shouting 'Mumbai' and 'brother'
- Cordon put up outside entrance but the building was not evacuated
Police and fire crews were called to a security alert at the BBC this morning after a man threatened to set himself on fire as witnesses claimed he doused himself in petrol and brandished a lighter outside new Broadcasting House.
Witnesses said they saw security staff leap on the man before he could light a fire and hold him down until police officers arrived at the broadcaster's offices near Oxford Street in central London.
He was seen being pinned to the ground by security guards and officers, while BBC Staff poured sand over the spilt liquid, believed to be petrol, as police restrained the man.
He was detained by officers, while police remained at the scene as a security measure. No one was harmed during the incident.
'Police officers remain at the BBC, Portland Place, W1 after they were called to a man threatening to set fire to himself,' a spokesman from the Metropolitan Police said.
'Two bags at the location were examined by specialist officers and found to be non-suspicious.'
Emergency services were called shortly after 9.10am this morning. Police said that a cordon had been put up around the building, which is home to television and radio studios, but staff had not been evacuated from inside.
'Officers attended and the man has been detained,' the police spokesman added.
'A cordon is in place around the front of the building. Officers are working closely with security. The building has not been evacuated.'
One eyewitness, Chris Slegg, a BBC London sports journalist, said he saw a man douse himself with petrol while shouting the words 'Mumbai' and 'brother'.
He said he alerted security staff after he saw a man empty a canister of clear liquid on the floor.
'It was just after 9am and I, like a lot of people there, was walking to work,' he said.
'There were about ten people in the piazza and I think they were probably all BBC employees.
'I saw a man, on his own, emptying a canister onto the floor and he was shouting. I heard the words "Mumbai" and "brother".
'I smelt the petrol immediately.
'I'm guessing he was in his 30s or 40s, but I can't be sure.
'It was outside the main entrance so I walked about 25 yards to my entrance and alerted our security guard.
'The whole security team dealt with the incident in a very professional manner. They had everything under control.
'It was our security team who really dealt with the incident well and about two minutes later when I got in, people were looking out the window and I could see the guards had wrestled him down.
'I think the police arrived about half an hour later, though I couldn't be sure."
He added: 'My first instinct was that he seemed to be blaming the BBC for something.
'He was shouting at the main entrance doors. I couldn't hear what he was saying exactly, but I did hear the words "Mumbai" and "brother".
'It was a pretty worrying thing to witness, but I think that our security team acted so professionally that we all felt as calm as it was possible to feel.'
Photographer Ian Lawrence, 41, who was waiting by the entrance to BBC Radio One, said: 'I was here just waiting in my car and I heard some people shouting. At first I didn't think anything of it but they kept shouting.
'I got out of my car and saw two BBC security guards wrestling with the guy and he was still shouting.
'They were great. They just jumped on him before he could do anything.
'Then the police came and he was put into the van and he was still shouting.
'I saw there were two milk bottles which had a clear liquid in them. They brought some sand out and poured what was left into that. That was when you could smell it was petrol.
'The adrenaline was really pumping. It's not what you expect outside the BBC.'
Many BBC staff took to Twitter, including technology correspondent Rory Cellan-Jones.
'Some kind of incident at New Broadcasting House - police and fire brigade here,' he wrote.
He later added: 'Earlier incident involved man pouring petrol over himself outside BBC - he was tackled by security guards.'
Radio journalist Robin Edwards said the man had been holding a lighter, although police have not confirmed this.
He wrote on the social networking site: 'Man poured petrol over himself outside BBC New Broadcasting House, holding lighter. Now on floor with security on top. Police on scene.'
'From what witnesses tell me, doesn't sound like it was a political protest,' he wrote, and added, 'Very strong smell of petrol now every time someone opens the door.'
And infographic designer Mark Bryson said: 'Someone just attempted to set themselves on fire outside BBC New Broadcasting house. Security tackled them before they could start the fire.'
A BBC spokesman confirmed the incident had taken place.
'We do not have anything further to add to the Met's statement,' she said. 'We wouldn't comment on security matters.
A spokesman from London Fire Brigade confirmed firefighters had attended the scene, but said they had not needed to take any action.
Broadcasting house was officially opened in May 1932, and has since been extensively renovated with a new extension, which known as new Broadcasting House, completed in 2010.
The extension contains the BBC News departments, including studios for the BBC News channel and BBC World News, while Radio 1 and 1Xtra are also housed there.Radio 3, Radio 4, Radio 4 Extra and the World Service are based in refurbished studios within the building.