Matthew Moore, Jakarta – In Indonesia's better hotels you will sometimes see signs that read: "No Durians Past This Point." Because the prickly green fruit has a smell that lingers like a blocked drain, staff are taught to treat it like non-paying guests.

Yet somehow the appalling smell of the durian has ensured the enticing flesh within is even more desired. Now, thanks to the generosity of the German Government, Indonesia's lovers of durian can take their infatuation a stage further, with durian-flavoured condoms.

For some, the mere thought of such a device would be contraceptive enough. But according the man who is making them, durian-flavoured condoms are quickly finding their place in the market.

Christopher Purdy decided to make the condoms in the hope of encouraging Indonesians to talk about a subject that is usually taboo. Mr Purdy runs a non-profit group called DKT International, which tries to change behaviour as a way of improving people's health.

In Indonesia that means lifting the level of condom use to head off an explosion in HIV infection, especially in high-risk groups such as prostitutes. Indonesia's population of 220 million uses 70 million condoms a year, while in nearby Thailand the rate of condom use is more than four times higher.

Mr Purdy believes that if he can get people talking about condoms, then more people might be brave enough to buy and use them, which is why he came up with the idea of flavouring them with durian in the first place.

"There a terrible embarrassment in talking about sex here and with condoms there's a very heavy stigma," he said. "It struck me durian condoms would be a great way of getting people talking about them, possibly kids even talking to their parents about them."

Although Indonesia had a successful family planning program under former president Soeharto, it relied on injections and the contraceptive pill more than condoms, which were really only used for illicit sex.

The stigma still attached to condoms is Mr Purdy's major hurdle in trying to contain HIV. "The HIV trend is pretty frightening. Five years ago the numbers were in the hundreds, now the estimates are 100,000 to 120,000."

In the three weeks since they were released onto the market for their "soft launch", more than 250,000 durian-flavoured condoms have been sold, a figure Mr Purdy says is "quite remarkable".

With aid funding from the German Government, as well as the Bill and Melinda Gates Foundation, Mr Purdy's group produces a range of cut-price condoms. Many of their condoms sell for 10 cents each, although the new durian range will be unsubsidised and cost three times that amount.