Sorry but you might incur some loss here.
You made a terrible mistake by not having a copy of his passport, ie you are required to have these information. See if he willing to settle with you half-way.
One alternative is to engage those aggressive but legal type debt collector. I heard they have a way of pressurising the guilty party into submission.
In any case, you should take a video of his behaviour, together with pix of his family and stomp it or send it to Temasek Times.
You made a terrible mistake by not having a copy of his passport, ie you are required to have these information. See if he willing to settle with you half-way.
One alternative is to engage those aggressive but legal type debt collector. I heard they have a way of pressurising the guilty party into submission.
In any case, you should take a video of his behaviour, together with pix of his family and stomp it or send it to Temasek Times.