Prosecutor General Haruo Kasama expressed his view Monday that recording entire interrogations will make investigations difficult.

Prosecutors recently have opted to record portions of interrogations at their discretion amid calls to enhance transparency after repeated allegations of forced confessions. But after more revelations that innocent people were being convicted and prosecutors had fabricated evidence, public voices have only grown further for entire interrogations to be taped.

"Recording entire interrogations will make it difficult to use certain techniques," Kasama, the nation's top prosecutor, said at the Japan National Press Club in Chiyoda Ward, Tokyo.

He cited an example in which, say, five people are arrested for a crime and the first one to confess would fear retaliation if this became known to the other four. Kasama reckoned that separately taping each suspect's individual interrogations would reveal who sang first, and thus criminal suspects would be prompted to clam up.

The first suspect to confess often tells prosecutors not to let other suspects know this, Kasama said, adding that when prosecutors are about to write up their interrogation report, the first to confess will urge such an entry not be made in order to avoid letting other suspects know.

Kasama said he personally feels that special investigative teams made up of prosecutors should only be allowed to arrest, and not indict.

He also said he views the incidence of prosecutors faking evidence as a systemic problem rather than that of an individual, special investigative team member, as was the case at the Osaka District Prosecutor's Office involving Tsunehiko Maeda last September.

"Fabricating evidence is inexcusable," Kasama said.