Its robust approach has caused frustration among investigators, according to law enforcement sources. Identifying anonymous Twitter members can be very difficult, particularly without the technical log data that the firm holds. In September the tour operator Thomas Cook was forced to take out a High Court injunction to block abuse by what it believed was a rogue employee it could not identify.
Unlike Facebook, which has staff in Ireland dedicated to working with police, Twitter insists that British investigators use complicated international treaty arrangements to obtain information from its headquarters in Silicon Valley.
For police to obtain communications data such as details of when and where Twitter members logged into their account, they must use Britain's mutual legal assistance treaty with the United States and get a court order in California. The process can cost up to £10,000, according to a source with detailed knowledge of the arrangement.
Twitter also has a policy of informing members if they are the target of an inquiry, unless it is forbidden by law, to allow them to challenge it. Compared to other web firms, it also has a robust stance towards attempts to identify its members and has itself fought court battles to resist requests.
At a Parliamentary hearing in September, Twitter's global head of public policy Colin Crowell argued that it was not able to be as much help to police as other social networks.
"We probably get fewer requests for user data than some of the other services, only because the nature of Twitter is that most of what happens there is already public anyway," he told MPs scrutinising new laws to give authorities greater access to communications data.
"Law enforcement oftentimes simply has to go to the web on its own and can obtain the relevant Tweets that they were looking for.
"Twitter also tends to collect less user data than perhaps some of the other services. For example, we do not collect information from our users about gender, age, home street address or things of that nature."
Overall, the Transparency Report showed a growing demand from international authorities for information on twitter users, however. Requests were up 20 per cent compared to the previous six months.
As it released the data, Twitter said it hoped "to raise public awareness about these invasive requests".
"All of our actions are in the interest of an open and safe internet," said legal policy manager Jeremy Kessel.
Twitter is likely to come under official pressure to relax its procedures as its popularity continues to grow, experts said.
"This is a global problem," said Martin Hoskins, an independent data protection consultant who formally dealt with police requests at the mobile operator T-Mobile.
"Authorities everywhere are looking to speed up these requests and make the process simpler."
It is understood that officials have already held talks designed to "streamline" the bureaucratic process involved in obtaining communications data from the United States via the mutual legal assistance treaty, which would ease attempts by police to get information from Twitter and other technology firms in Silicon Valley.