Hi, I found this on a dodgy-looking website but you might be able to corroborate it elsewhere:
Then, in 1951 Wendell Phillips somehow convinced Yemen’s young Imam ibn-Yaha, who had recently come to power by beheading his regent and First Minister, to allow Americans to dig at Ma’rib. This was a highly unpopular move among the infidel-hating people of the ancient queen’s capital. In a little less than a year of nervous excavation, the Phillips expedition uncovered an exquisite 60 by 82-foot temple within a 250 by 330-foot royal or sacred enclosure bounded by a 30-foot wall. This was said to have been the queen’s royal apartment.
Hope this helps, Simon