The official campaign of leftist presidential contender Hamdeen Sabahi says it has identified several electoral violations since voting began on Tuesday in Egypt's presidential election.

In a report obtained by Ahram Online, Sabahi's campaign says members of its team have been detained at polling stations in several governorates while others have been barred from entering.

It also alleged that illegal campaigning has been taking place inside and outside several stations, with loudspeakers blaring pro-army songs at a station in Cairo and police officers using laptops to sway citizens' votes in Minya. Campaign flyers were being passed out by a station in Qalioubiya governorate.

The report said that the head of the campaign's legal committee in Giza, lawyer Ahmed Hanafy, was arrested after being beaten by police while trying to handle a problem at the station.

Hanafy is now being detained at Al-Warraq police station in Giza, according to Sabahi's campaign.

Several agents have been barred from entering polling stations in the governorates of Suez, the Nile Delta's Ismailiya and Qalioubiya and Upper Egypt's Minya, the report said.

In Qalioubiya, supervising judges refused to acknowledge representatives of both candidates on grounds that they did not have permits from the country's high electoral committee, the campaign said. Judges showed up late in Qalioubiya and Aswan, where an unsealed ballot box was reported.

Sabahi is running against only one challenger, former army chief Abdel-Fattah El-Sisi, who is expected to win the two-day vote handsomely.

El-Sisi, who quit his post as army chief and defence minister to run for president, has received cult-like adulation after he led the ouster of divisive president Mohamed Morsi last July and cracked down on his Muslim Brotherhood movement.

Sabahi reiterated on Tuesday that "Egyptians' votes will settle the electoral battle rather than pre-emptive expectations."

He told reporters while queuing to cast his vote at a Giza polling station that he "would not accept any executive position" if he lost the election. The veteran dissident, who was jailed several times under previous presidents, said he would remain in the opposition camp if El-Sisi is elected president.