The budget for the 2012 London Olympics has increased once more after additions to both security and the opening and closing ceremonies were revealed.

The Department of Culture, Media and Sport's quarterly review indicated that the spend on security itself was to top £1 billion after a £271m addition.

Minister for Sport and the Olympics, Hugh Robertson, said: "As was always planned, the Government and LOCOG (the game's organising committee) have now undertaken detailed analysis of the numbers of security staff required to protect the more than 100 Olympic venues.

"As a result, to ensure a safe and secure Games, they have revised the numbers of trained staff required. We are therefore investing additional funds in providing nearly 24,000 venue security personnel plus specialist security equipment."

An extra £41m was also assigned to the opening and closing ceremonies, which are seen as a showcase for the games.

Beijing was praised highly for its ceremonies in 2008, which were seen as a precursor to a highly successful games.

"London's opening and closing ceremonies are a once-in-a-generation opportunity to showcase the very best of our country to four billion people around the world and have a potential advertising value of £2-5 billion," Robertson added.

The opening ceremony in London will be on July 27.