La Paz (AFP) - Luis Arce, the presidential candidate for Evo Morales's Movement for Socialism party, was immediately served with a subpoena as he returned to Bolivia on Tuesday following a self-imposed exile in Mexico.
Arce, who is due to stand for MAS in the May 3 election, is accused of a breach of duties and embezzlement during his tenure as economy minister.
Morales was in power for almost 14 years before resigning on November 10 following three weeks of at times violent protests against his controversial re-election in an October poll.
An audit from the Organization of American States found clear evidence of fraud. After resigning, Morales fled into exile in Mexico before settling in neighboring Argentina a month later.
He is barred from running in the May election and an arrest warrant has been issued for him -- the interim government accuses him of sedition and terrorism -- but Morales has vowed to return to his homeland to lead the MAS campaign.
When Arce arrived at the El Alto airport just outside La Paz, he was served with a subpoena by a police officer, a moment captured on video and widely shared on social media.
An image on the website of newspaper Pagina Siete shows Arce signing the summons, which requires him to appear before public prosecutors on Wednesday morning.
Rafael Quispe, the director of the Indigenous Development Fund, has called on Arce to be "summonsed, arrested and taken to jail" for his "alleged responsibility in the embezzlement of millions" from an indigenous fund while he was economy minister.
However, Attorney General Heidy Gil said that no arrest warrant has been issued for Arce.
He was met at the airport by his running mate, former foreign minister David Choquehuance, amid cheering supporters waving the "Wiphala" indigenous flag.
Morales, 60, was Bolivia's first ever indigenous president and MAS derives much of its support from indigenous communities that were often marginalized under previous governments.
Arce, 56, left the airport without speaking to the press as his supporters chanted: "Arce, president," and "Fight, friend, the people are with you."
However, he later wrote on Twitter: "Together with the people, we will win. I feel a lot of affection and now we'll continue on our road to the presidency."
Arce is considered the mastermind behind Bolivia's economic success under Morales.
MAS led the most recent opinion poll with 26 percent -- although the survey was conducted before Arce was named as the party's candidate.
Centrist Carlos Mesa, who came second to Morales in the disputed October election, and right-winger Luis Fernando Camacho each polled 17 percent.
Interim president Jeanine Anez -- who controversially announced her candidacy on Sunday despite having previously insisted her role was only to lead the country into elections -- was in fourth place with 12 percent.
Candidates have until February 3 to register.