Intrigued regarding strange car registration numbers

I work at All Seasons place in Bangkok and indulge in the nasty habit of smoking!

Over the last couple of days there has been some sort of convention involving the Tourist Police at the Conrad hotel, they tend to park their cars on the back road of the complex, which happens to be in the same location as one of the smoking areas.

Over the last two days, there have been two white BMW 520d saloon cars parked on this back road, with the occupants attending this seminar, nothing strange about this, except the registration numbers of these BMW's, one was BE01 and the other IT01, no Thai lettering, no province, no official lettering / numbering to indicate a foreign diplomat etc. White background, black letters / numbers as per normal vehicles.

On the back windscreen of each vehicle was a sticker, BE01 was BE Minister and IT01 was IT minister, both vehicles were supplied by BMW Thailand (not a BMW dealer) according to the plate holders.

Checked whether these ministries exist in Thailand and seemingly not.

Not important, just intrigued, anybody any idea who these cars belong to persay?