TOKYO (Reuters) - Tons of relief goods have been delivered to victims of Japan’s catastrophic earthquake and tsunami from a dark corner of society: the “yakuza” organized crime networks.

Yakuza groups have been sending trucks from the Tokyo and Kobe regions to deliver food, water, blankets and toiletries to evacuation centers in northeast Japan, the area devastated by the March 11 earthquake and tsunami which have left at least 27,000 dead and missing.

Yakuza are better known for making money from extortion, gambling, pornography and prostitution, as well as for the often-elaborate tattoos covering much of their bodies.

But disasters bring out another side of yakuza, who move swiftly and quietly to provide aid to those most in need.

As with the devastating 1995 Kobe earthquake, government workers were slow in reaching afflicted areas, and the 300,000 or so survivors, so yakuza groups stepped in quickly, and in many cases, were first on the ground.

Such actions stem from yakuza knowing what it’s like to have to fend for yourself, without any government or community support, because they are considered outcasts.

Many gang members faced discrimination and come from minority populations such as ethnic Koreans or “burakumin” - those who work in businesses seen as related to death, such as butchers and leather tanners.

“Yakuza are dropouts from society,” said Manabu Miyazaki, a prolific author who has written more than 100 books about yakuza and minorities.

“They’ve suffered, and they’re just trying to help other people who are in trouble,” said Miyazaki, himself the son of a former Kyoto yakuza boss.

Others see ulterior motives to the groups’ charity.

“If they help citizens, it’s hard for the police to say anything bad,” said Tomohiko Suzuki, a journalist who has written several books on Japan’s underworld.

“The yakuza are trying to position themselves to gain contracts for their construction companies for the massive rebuilding that will come.”

One yakuza boss rejected such criticism.

“It takes too long for the arm of the government to reach out here so it’s important to do it now,” the Weekly Taishuu magazine, which specializes in yakuza affairs, quoted a top yakuza as saying.

“Our honest sentiment right now is to be of some use to people,” said the boss, who declined to be identified.

GANGSTERS’ CODE OF GIVING

Yakuza groups have so far dispatched at least 70 trucks to the quake zone loaded with supplies worth more than $500,000, according to Jake Adelstein, an expert on yakuza who lives in Tokyo and is writing two books on the Japanese syndicates.

The gangs’ charity is rooted in their “ninkyo” code, Adelstein says, which values justice and duty and forbids allowing others to suffer. “In times such as earthquakes, they put their money where their mouths are,” he said.

Atsushi Mizoguchi a freelance writer and yakuza antagonize who has written about organized crime for 40 years, also gives the yakuza the benefit of the doubt.

“Rather than a PR effort, I think it’s actually good intentions,” said Mizoguchi, who has angered the yakuza so much that he has been stabbed twice in attacks by gang members.

But yakuza shun the spotlight regarding their relief work.

Adelstein explains that there is an informal understanding between yakuza and police who tolerate the gangs carrying out such charitable work, but not seeking publicity for it.

“What they seek most is self-satisfaction,” said Miyazaki, the son of the former yakuza boss. “It’s not for pay, but for pride.”

There are an estimated 80,000 yakuza in Japan. The Sumiyoshi-kai and Inakawa-kai, the second and third biggest organized crime syndicates, are believed to be the most active in the earthquake-tsunami disaster relief.

In a phone call to the Inakawai-kai headquarters in Tokyo, a man from the gang’s “general affairs division” brusquely told Reuters: “We don’t talk.” A faxed request to speak with the Inakawa-kai’s No.2 leader went unanswered.

Part of the reason for the yakuzas’ reluctance to receive attention stems from stepped-up enforcement after a 1992 anti-gang law and increased crackdowns by the National Police Agency over the past year, which have heightened anti-yakuza sentiment among the public.

But there have been no reports of donations being refused -- perhaps because there is no indication who supplied them.

And, says author Suzuki, this is not the time to nitpick over the origins of emergency goods.

“When it’s life or death, you don’t care where your food comes from,” he said.