The two were not available to comment despite requests from Reuters.
Anupong and Prayuth served with the Queen's Guard, an elite unit with greater autonomy from the rest of military, with its allegiance foremost to the monarchy rather than the direct chain of command, said Paul Chambers, director of research at the Institute of South East Asian Affairs in Chiang Mai, Thailand.
While most Thais still express steadfast loyalty to 86-year-old King Bhumibol Adulyadej, his throne is seen as entwined with the political forces that removed Thaksin, especially ultra-nationalists who in the past have worn the king's colour of yellow at protests and now back Suthep.