Australian authorities are increasingly monitoring web users' activities, as worldwide governments increasingly track the online lives of citizens.

In the first six months of the year, Australian authorities made 523 requests to Google to access the data of 841 Gmail and YouTube users.

Google complied with 64 per cent of those requests, down 1 percentage point since last year.

Worldwide, authorities made 20,939 requests to Google for information on its users - a sharp jump on the 12,539 requests in the second half of 2009.

Authorities made 1791 requests that Google remove 17,746 items in the first six months of 2012. Most of the requests came from government and law enforcement authorities.

The figures, contained in Google's latest transparency report, show a steady rise in the number of requests for access from Australian governments since it first began publishing the data in July 2009.

''The number of requests that we receive for user account information as part of criminal investigations has increased year on year,'' Google said in a blog posting. ''The increase isn't surprising, since each year we offer more products and services.''

Australian governments also made 92 requests to remove items from Google websites, including YouTube and search engine results. Most of the requests were made for ''privacy and security'' reasons, or over defamation and copyright issues. with AAP