Michael Raphel, 28, of Oxford, England, said he was visiting London to celebrate a friend's birthday and parked his car Nov. 7 in an area that police later informed him was less than a quarter mile from 10 Downing Street, Prime Minister Gordon Brown's residence and office, and was along the route of parade due to take place the following day, The Daily Telegraph reported Monday.
Raphel said he returned to his car at 2 a.m. to find it surrounded by anti-terrorism police.
"They explained that because I was seen running from the car, and because of the parades the next day, it had heightened their suspicions," he said.
He said police told him they carried out two controlled explosions on the car.
"When I got back to the car, the driver and passenger windows had been blown out and the bonnet and boot had come open with the force," Raphel said.
Raphel said he plans to seek compensation from police but experts said he is unlikely to be successful since the car was illegally parked.