The number of special surveillance devices ordered in Bulgaria has increased three times in the last three years and reached 15,946 in 2010, according to data from Bulgarian courts.

In the same time, their efficiency has decreased, since the percentage of tapped conversations used as evidence in investigations dropped from 15% in 2008 to 12% in 2010.

The data was presented Monday at a national meeting between appellate, district and military courts in Bulgaria and the Prosecutor's Office, regarding problems in the use of special surveillance devices.

The Deputy Chair of the Supreme Court of Cassations, Grozdan Iliev, announced that eavesdropping is conducted mostly in the regions of the cities Sofia and Plovdiv.

In his words, out of the total 5598 special surveillance ordered in 2008, more than 4500 were used in these two regions. In 2009, a total of 11,561 permissions for eavesdropping were issued in Sofia and Plovdiv.

"The conclusion is that we have a weak efficiency of the special surveillance devices, while at the same time we constantly increase their use," Iliev said.

He reminded the 2007 ruling of the European Court of Human Rights, on the basis of data from 2000, which stated that secret monitoring is used excessively in Bulgaria.

"Now, the statistics for special surveillance devices shows that they are used a lot more," Iliev said.

Bulgaria's Chief Prosecutor, Boris Velchev, has also confirmed that magistrates approve more than 99% of the requests for eavesdropping.

"There could be improvements in all directions. I wish we could reconsider the philosophy with which we treat the results from the special surveillance devices. They should not be treated as the absolute evil," Velchev said.

The Chair of the Supreme Court of Cassations, Lazar Gruev, urged judges and prosecutors to find the balance between the democratic rights of citizens and the effective fight against crime, which requires the use of special surveillance devices.

"We should remember more often that Bulgaria has a Constitution, which defines and guarantees the basic rights of citizens," Gruev said.

The data showed that the most requests for eavesdropping are with regards to drugs and customs smuggling.

The topic for the use of special surveillance devices stirred Bulgaria after the scandal with leaked discrediting conversations of senior government officials began in January.

The so-called "Tanovgate" recordings have formally been leaked by two sources – the Galeria weekly and the marginal conservative party RZS ("Order, Law, Justice), both of which are deemed to be connected with Alexei Petrov, a former undercover agent arrested in a special police operation in February 2010, dubbed "the Octopus" and "the Tractor".

The tapes, whose authenticity remains disputed despite the fact that several institutions and alleged independent experts have come up with different conclusions on whether they were manipulated, contain alleged information that the government of PM Boyko Borisov is favoring certain companies and individuals with respect to investigations and appointments in the Customs Agency. All tapes are of conversations of Customs Agency head Vanyo Tanov.