GUATEMALA CITY (AP) — A high court ruling barring a crusading former prosecutor's candidacy has turned Guatemala's presidential election on its ear less than a month before the vote.

The rejection of Thelma Aldana's appeal means at least two of the top three candidates according to polls will not appear on the June 16 ballot.

And analysts said Thursday the Aldana decision in particular appeared to spring from fears over her zealous prosecution of corruption.

In the words of one observer: "I think Thelma Aldana terrifies them."

Already Zury Ríos Sosa, daughter of an ex-dictator, was disqualified. Mauricio Radford was barred over a pending corruption case. And yet another would-be candidate is behind bars in the U.S. on drug charges.

Front-runner Sandra Torres is also awaiting a decision on whether she'll be can run.