British police believe the Real IRA is carrying out a parallel bombing campaign in Ireland and Britain and may be operating a bomb factory in London.
Deputy Assistant Commissioner Alan Fry spoke of the possibilty as forensic scientists investigating the BBC bomb were today examining fragments of blue plastic containers which are similar to those used in other bomb attacks in Northern Ireland.
British anti-terrorist branch officers believe the home-made explosives may have been packed into one or more blue barrel-type plastic containers, each of which can contain up to approximately 80lbs of explosives.
The bomb at the TV Centre was packed into a red taxi which it blew up near the BBC building in Wood Lane, west London, last Sunday, leaving one person injured.
Numerous pieces of blue plastic were recovered over a wide area following the explosion. The material is still being forensically examined.
Containers of this type have been used since February last year in terrorist attacks in Ireland which are thought to have been the responsibility of the Real IRA.
In the early hours of the morning on June 30 last year, there was a large explosion on the Belfast to Dublin railway line at Newry.
A blue plastic barrel-type container was found concealed nearby which contained explosives was similar to the container which police believe may have been used in the explosion outside the BBC.
Deputy Assistant Commissioner Alan Fry said: "We are unable accurately to estimate the amount of home-made explosive used in the device which detonated with such devastating effect.
"This was a totally reckless act which I have no doubt was designed to maim or kill."
"At this stage we do not know if the device was made here on the mainland or if it was brought over from Northern Ireland."
PA