The son of Pink Floyd guitarist David Gilmour has apologised for swinging from a Union Flag on the Cenotaph during Thursday's student protests.
Charlie Gilmour, 21, said he was "mortified by his moment of idiocy" when he climbed the memorial to Britain's war dead in central London.
The Cambridge University student said he did not realise it was the Cenotaph.
A 19-year-old man has been arrested on suspicion of causing criminal damage in relation to the Cenotaph incident.
Mr Gilmour said in a statement: "I would like to express my deepest apologies for the terrible insult to the thousands of people who died bravely for our country that my actions represented.
"I feel nothing but shame. My intention was not to attack or defile the Cenotaph.
"Running along with a crowd of people who had just been violently repelled by the police, I got caught up in the spirit of the moment.
He added: "Those who are commemorated by the Cenotaph died to protect the very freedoms that allow the people of Britain the right to protest and I feel deeply ashamed to have, although unintentionally and unknowingly, insulted the memory of them.
"Ignorance is the poorest of excuses but I am sincerely sorry."
Mr Gilmour is currently studying history at Girton College, Cambridge.
He is the son of writer and journalist Polly Samson and his father is the poet and playwright Heathcote Williams, her first husband.
He was later adopted by the Pink Floyd musician when she remarried.