Amnesty International says thousands of convicts may have been executed in China and at least 26 others were put to death in other Asian countries in 2009 despite growing global support for abolition.

The execution of two Japanese men for murder on Wednesday reignited a debate over the relevance of judicial executions in the 21st century.

"It made me again think deeply about the death penalty, and I once again strongly felt that there is a need for a fundamental discussion about the death penalty," Justice Minister Keiko Chiba said as she announced a review.

Even China is taking a look at its laws by launching a review of the 68 offences currently punishable by death, according to state media reports.

But in Singapore, British writer Alan Shadrake, 75, will appear before the High Court on Friday to face contempt of court charges after launching a book titled "Once a Jolly hangman: Singapore Justice in the Dock."

In the book, Shadrake describes candid conversations with a retired hangman, Darshan Singh, whom the author says executed some 1,000 local and foreign criminals in a career spanning nearly half a century.

Shadrake, based in Malaysia and Britain, is out on bail and undergoing a separate investigation for criminal defamation relating to passages in the book seen as questioning the integrity of Singapore's judiciary.

Contempt of court is "punishable by imprisonment and/or a fine, with no limits on either," said a statement from the Attorney-General's Chambers.

Among human rights groups, Singapore is known as the execution capital of the world because of the number of hangings it has carried out relative to its population, which currently stands at just five million.

Singapore keeps its tally of executions secret and maintains that the use of the death penalty for murderers and drug traffickers has been crucial in keeping the crime rate low in the island, widely acknowledged as one of Asia's safest countries.

Amnesty International estimates that Singapore executed at least 420 people between 1991 and 2009.

"Our view is that there is a growing global sentiment against the death penalty," Phil Robertson, deputy director for Asia at Human Rights Watch, told AFP, adding that countries that still execute convicts are "seriously out of touch" with international opinion.

Amnesty says China was believed to have executed thousands of people in 2009 -- more than the rest of the world combined -- although the figures are a state secret.

The London-based human rights group said at least 26 people were known to have been executed in other Asian countries in 2009, led by nine in Vietnam and seven in Japan.

In Malaysia, the government rarely releases information about executions but activists said that 358 hangings were carried out between 1981 and 2005.

"The death penalty is inhumane," said lawyer Charles Hector, from rights group Malaysians Against Death Penalty and Torture.

Thailand has executed 325 convicts, including three women, since 1934, when it began using firing squads instead of beheadings, according to government figures.

It introduced lethal injection in 2003 and has since executed six people by this method.

India has not carried out any executions since 2004 and has hanged only two people since 1998.

The last available government statistics show that 308 people were on death row at the end of 2007, although no breakdown was provided about the status of prisoners in the appeals process.

Those waiting to hear their fate include the killers of former prime minister Rajiv Gandhi, who was assassinated in 1991, and Mohammed Ajmal Amir Kasab, convicted for the 2008 Mumbai terror attacks.

In Taiwan, a total of 541 people have been executed since 1981, according to figures compiled by Taiwan's Justice Ministry.

The last took place in April, when four prisoners were executed after the justice minister stepped down, having caused a political storm by saying she would not allow any convict to be put to death during her term.

In Indonesia, executions are carried out by firing squad. The last one was in November 2008 when three extremists behind the 2002 Bali bombings were shot. - By Agence France-Presse, 29/7/2010