The flame, which is being carried by some 580 torchbearers in total, visited London landmarks including the Abbey Road crosswalk made famous by The Beatles. The relay will end at the Olympic Stadium in east London.
Organizers were trying to make sure the flame will arrive on time for Wednesday night's opening ceremony — the relay was running around two hours late.
The London Organizing Committee said that as a contingency plan, officials had arranged for part of the flame to be sent to the stadium separately to make sure the ceremony could start on time. The relay would continue, organizers said.
The 24-hour torch relay began Tuesday night in Stoke Mandeville, about 45 miles (72 kilometres) northwest of London, the birthplace of the Paralympic Games.
Queen Elizabeth II, Prince William and the Duchess of Cambridge are expected to join thousands at the opening show, which will kick off 11 days of competition featuring 4,300 athletes from more than 160 countries.