French police took the unprecedented move on Tuesday of taking former president Nicholas Sarkozy into custody as part of a corruption probe. Earlier, investigators detained the politician's lawyer and two magistrates for questioning. Under French law, police can detain the former president for up to 24 hours without filing charges. 

Although, as the Guardian noted, it's not clear at this point whether he's being questioned as a witness or a suspect, the development will have an obviously negative effect on Sarkozy's future political ambitions. It's widely believed that the former president wanted to pull a Grover Cleveland and reclaim his old job in 2017. As it turns out, the corruption probe pertains to one of his former successful campaigns, in 2007.

It's all a bit complicated, but the upshot is that police suspect Sarkozy was kept in the loop on a different investigation into a claim that his campaign accepted a hefty donation from the late Libyan dictator Muammar Gaddafi. As part of that investigation, police tapped Sarkozy's phone. Those phone taps also gave police evidence indicating that the politician was tampering with the country's justice system by getting inside information on inquiries into his past. One of the two detained magistrates detained on Tuesday was allegedly promised a cushy promotion to Monaco in exchange for that information.

Sarkozy has denied any wrongdoing both in the Gaddafi inquiry and in the subsequent corruption investigation. His lawyer, Thierry Herzog, condemned the phone tapping earlier this year, claiming that the entire thing was "political" and a "monstrous violation." The phone tapping operation was not illegal, as the New York Times noted, but it is a "highly unusual" move for French investigators. 

This is hardly the first time a recent president of France has faced corruption charges (see: Jacques Chirac). But according to Reuters, this is the first time a former French head of state has been held for questioning in the country's modern history— the full scope of French history, of course, has been much less kind to former heads of state.