Are there bogus donors out there?

Hi
I don't know if anyone can help with this.
I volunteered for a really small non-profit in Nicaragua. They are totally dependent on donations, and have received an offer from a "business man and philanthropist based in the UK" for £2,000. This is a really big deal for them adn they don't want to pass up on opportunity.
For some reason that I haven't yet got to the bottom of, the donor won't use the paypal option, or transfer funds from his bank, or ask his bank to produce a US$ cheque for him to send over to the organisation.
He can only donate if it can be processed in the UK.

The organisation is trying to be helpful, and i will always hep them however I can, and they have asked if i can help this guy out.
I will - but only if it is legit.
It seems he wants me to receive AND CASH the cheque to make the donation. I don't get this. He says he is based in the UK so I do not get how it is any easier for me to send the money over than it is for him.
He is now saying he is also going to ship them 5 PCs and will send me a cheque, via a client, for £5,000 and would like me to take the £2,000 and send it to the organisation and then help him get the other £3,000 to the people shipping the PCs.

Even as I write this I know it sounds dodgy - but if there is the slightest chance it isn't then I don't want to scupper this for the organisation.
Has anyone heard of anything like this? Can people use charities to launder money? I don't even know if this would be laundering - don't know much about it.

We are following it up - I've searched on the internet, but can't find any trace of the guy; I am checking with the organisation that they are ok with me asking him right out why it has to be done this way, and if the PCs are really part of the deal, but in the meantime - if anyone has any ideas, seen this before, etc, please reply.

Many thanks
Lucy