Japan has opened up its death chamber to local media for the first time, as part of an attempt by the justice minister to stoke debate about the death penalty.

Justice Minister Keiko Chiba has called for more disclosure and discussion on executions in light of a lay judge system introduced last year.

The new system allows ordinary citizens, along with professional judges, to hand down death sentences.

Despite opposing capital punishment, Ms Chiba signed off on the executions of two convicted killers and attended their hangings last month.

She also set up a group to study the death penalty.

TV footage from inside the Tokyo Detention House showed the trap door, the viewing room and rooms where the inmate can meet a cleric, with a Buddhist altar and a Buddha statue.

The noose was not shown.

'There was the smell of incense ... The impression was that of sterile objects in a clean, carpeted room,' said a reporter from broadcaster NTV.

Footage also showed the 'button room', where three prison officers press a button at the same time to open the trap door, so that it is not clear which button opened the door.

Japan has 107 inmates on death row.

Japan and the US are the only Group of Eight rich countries that retain capital punishment.

An overwhelming majority supports the death penalty.

Last year, 86% said in a government survey that retaining the death penalty was unavoidable, up from 80% in 1999. However, a recent NHK public TV survey put support at 57%.

Experts are concerned at how little the public knows about the death penalty.

The Justice Ministry in 2007 started releasing the names and crimes of inmates sentenced to death, but critics say the ministry still restricts information.

'(We) demand that the Japanese government ... fully disclose the reality of the death penalty system,' human rights group Amnesty International said in a statement.

While some in the public were disturbed by the disclosure of the execution chamber, others welcomed the move.

'I think it's an honest and positive step to show the place where peoples' lives are taken in accordance to Japanese law,' said Kazutoshi Yasui, 26. 'It's better than hiding it.'