I don't know if this helps but I tried entering the number you gave into Googel, but I entered it in the normal British format - 02079061700. It gave me this:
Phillip Weisberg Ltd
137-139 Brent Street
London
NW4 4DJ
Property Developers
Fax: 02079061700
It seems to have nothing to do with ID theft, but appears to be a fax number calling you by mistake. Perhaps you could fax them back and ask them to stop?