The memorial commemorating the victims of the July 7 bombings on London has been defaced just hours before survivors and bereaved families gather to commemorate the ninth anniversary of the attacks.
The stainless steel columns of the memorial in Hyde Park, central London, were daubed with red and black slogans overnight with the messages "4Innocent Muslims" "Blair Lied Thousands Died" and "J7 Truth".
These pictures posted on Twitter by broadcast journalist James Banks, for London Live, shows the full extent of the defacement.
A spokeswoman for the Royal Parks said the slogans had now been removed after they were discovered early this morning by the park's manager.
She said: "We found it this morning. It has now been removed and the memorial can go ahead as planned. Obviously, we are very disappointed."
The monument honouring the 52 dead in the attack on London's transport system in 2005 cost nearly £1 million and has 52 stainless steel columns 3.5m tall.
It was unveiled in 2009 at a memorial attended by the Prince of Wales, the then Prime Minister Gordon Brown and other political leaders.
The columns are grouped together in four clusters, reflecting the separate locations of the bombings - Tavistock Square, Edgware Road, King's Cross and Aldgate.
Four suicide bombers detonated their rucksack devices near these locations on the morning of July 7 2005, killing the 52 and injuring hundreds of others, some seriously.
Graffiti was scrawled on the memorial in 2009 two weeks after its dedication ceremony on the fourth anniversary of the attacks.
John Falding, whose partner Anat Rosenberg, a 39-year-old charity worker, was killed in the Tavistock Square bus bomb, condemned the vandalism.
"It is quite shocking, whoever did it was aiming for publicity and to cause maximum grief," he said.
He said he would not be attending the event today but would be observing the anniversary in "quiet" with candles in memorial to his partner.
Scotland Yard said police had launched an investigation into the vandalism.
A statement said: "Officers were called by a member of the public shortly before 3.30 this morning and informed of the graffiti, which is being treated as criminal damage.
"The graffiti consisted of several short sentences written in red and black paint and has now been cleaned off the memorial.
"Inquiries continue led by officers from Westminster - there have been no arrests at this time."
A spokeswoman for the Tim Parry Johnathan Ball Foundation for Peace, which is organising the memorial, said Transport for London and Royal Parks staff had joined in the clean-up of the graffiti.
"Today is about the families and the survivors, we are disappointed that it happened, especially for them, but the Royal Parks and Transport for London came out in force and it was cleaned up within a couple of hours," she said.
"They made sure that it is as it should be for today."
The Mayor of London, Boris Johnson, said: "I am shocked and saddened by this incident. It is completely unacceptable and the Metropolitan police is already investigating.
"I am pleased that the graffiti has been removed so quickly and that today's commemoration ceremony can go ahead as planned.
"The focus today should be, and indeed will be, on honouring the 52 innocent people who died on 7/7, the survivors and all those affected by the terrible events of nine years ago."