The Election Petitions Tribunal sitting in Abeokuta, the Ogun State capital, began sitting yesterday.
It warned petitioners not to contemplate trying to sway them.
Chairman of the three-man tribunal Justice Ebiowei Tobi said the body would observe zero-tolerance for corruption.
Other members are Justices Adekunle Lawal and Quadi Adamu Usman.
The tribunal granted the All Progressives Congress (APC) candidate in the March 28 National Assembly election, Dapo Abiodun, the right to inspect electoral materials at the Independent National Electoral Commission (INEC) office.
Abiodun is challenging the emergence of Buruji Kashamu of the Peoples Democratic Party (PDP) as the senator-elect of the Ogun East senatorial district.
The APC candidate said the election was rigged. He alleged that Kashamu induced voters with money.
“There were manipulations in some areas where the number of those who voted exceeded the number of those accredited for voting.
“The election results on Forms EC8A, EC8B and EC8Cs did not correspond in many polling units in four local governments – Ijebu North, Sagamu, Remo North and Ikenne – where the election was massively rigged in favour of Kashamu.
“We have facts at our disposal, unknown to them. This is the people’s mandate, freely given to me. And no amount of dollar-induced manipulations can take away my mandate,” said Abiodun.
The Tribunal ruled that the inspection be carried out between April 30 and May 5.