Pépin, who was the target of a series of anti-corruption raids last February, faces several charges including fraud, breach of trust, municipal corruption and conspiracy.
His son, Danny Pépin, and two other men, Peter Veres and Benjamin Sternthal, were also arrested this morning.
UPAC released a statement saying the charges are linked to an investigation that began in 2010 involving land sales, the construction of a library and the financing of a political party.
The four men were taken to Quebec provincial police headquarters to be questioned, and will be released on a promise to appear in court on Jan. 29.
Police have issued an arrest warrant for a fifth man connected to the investigation. He has not yet been located.