Sony appears to be weakening on the role of Blu-ray in the pornography industry.

The company has said that it will not allow its media to be used for pornography, but a survey of sellers at the Adult Treasure Expo 2007 in Chiba, Japan has shown that while Sony claims this policy is unchanged it is supporting the production of Blu-ray porn in other countries.

"In Japan, there are some problems. Companies cannot press Blu-ray discs because they cannot touch adult-related contracts," Kiyotaka Konno, director of administration at Assist, a Japanese company that authors and replicates DVDs for the adult industry in Japan, told IDG News.

"So we asked some makers in Taiwan to do the work, and then we import the discs back to Japan. The Taiwanese company was able to obtain a pressing machine from Sony and will start mass production in August."

The first films, 'JK,' 'Sex Vacation in Guam' and 'Eroist', are already being shipped back into Japan.

Blu-ray has already lost the market for the pornography industry in the United States, with most producers standardising on the HD DVD format, as it is cheaper to use.

Experts believe the decision of the porn industry to standardise on the VHS rather that Betamax format was a key factor in the last format wars.