Officials from Europol and Interpol also attended the meeting, which lasted several hours but did not result in a public statement.
However, a Metropolitan Police spokesman told journalists on Monday that the UK began supplying the latest investigation details from Scotland Yard and the intelligence services from Saturday.
"If they can offer any material assistance, we're not going to turn it down. In order to help us, they needed to know as much about our investigation as possible," the spokesman said.
At least 49 people were killed in the attacks on three underground trains and a bus in central London on Thursday, while 700 were injured, 60 of whom remained in hospitals on Monday.
A few sections of the London Underground railway system affected by the attacks remained closed on Monday.
Teams of workers are still toiling 20m below ground to remove bodies from the train wreckage in the tunnel between Russell Square and King's Cross.
Police said they did not know how many more bodies remained underground, and rescue workers said conditions were unlike any they had encountered before.
The bombers used high explosives and each device was lighter than 4.5kg but investigators have given no further details.
Police are still looking for the
remains of some of the victims
The first body publicly identified is that of Susan Levy, 53, a married mother of two from Hertfordshire. But it could take days to identify all the victims, forensics experts warn, as many were blown apart.
Investigators have not given any clues on possible suspects, but London newspapers have identified one as Mustafa Nasar - a Syrian suspected of being al-Qaida's operations chief in Europe and the alleged mastermind of last year's Madrid railway bombings.
London police refused to comment, but a US official said both nations were trying to locate Nasar.
And security officials in Poland searched the premises of a British citizen of Pakistani origin in connection with the bombings in London, a security official said on Monday.
Polish officers in the eastern city of Lublin conducted the search acting on a tip-off, a spokeswoman for the Lublin office of the country's Internal Security Agency said.
She said the man, whose name was not released, was not taken into custody.
Arrests and appeals
Three men, all Britons, arriving at Heathrow airport, were also arrested and released on Sunday, the first to be detained under UK anti-terrorism laws since the attacks.
Police have appealed to the public for images taken of the sites of the attacks, and mobile phone companies have been asked to store voicemail, email and SMS content from Thursday.
Meanwhile, British Prime Minister Tony Blair fended off opposition Conservative Party calls in parliament for an investigation into whether last Thursday's attacks could have been prevented.
Blair said late on Sunday that he would dismiss Conservative calls for an inquiry into the attacks, but would instead underline his confidence in the intelligence services.
Home Office Minister Hazel Blears told GMTV on Monday that the "last thing" the security services needed was an inquiry, as they were too busy with a massive investigation into the bombings.