A record 47 people were arrested in 2010 in investigations using authorized wiretaps, a Justice Ministry survey showed Friday.

The number of warrants issued by courts came to 34, also the largest since the Act on Wiretapping for Criminal Investigation took effect in 2000, it said.

Investigative authorities wiretapped 7,475 communications, all of which were cell phone conversations or text messages, in eight suspected drug-smuggling cases, one suspected gang-related murder and one case of gun possession.

The authorities found 1,326 of the communications were linked to the alleged crimes, according to the survey. This was the first time drug agents under the Health, Labor and Welfare Ministry used the wiretaps in their investigations.