The LP candidate accused security operatives of colluding with the ruling All Progressives Congress, APC, to manipulate the outcome of the poll.
Achonu also vowed that he would seek redress through the courts.
The LP governorship candidate alleged that his party supporters and voters were intimidated and harassed during the election, adding that the result declared by the Independent National Electoral Commission, INEC, does not reflect what truly transpired at the polling units.
Achonu said this on Sunday while addressing journalists in his country home.
He further said that, in contrast to INEC’s pre-election guarantees, voting took place in numerous places without BVAS accreditation.
According to him, “recorded evidences abound, such as that of a police officer who was beaten by voters for attempting to snatch a ballot box”.
He declared, “Today is a very sad day for democracy, for good governance, for equal opportunity, and freedom of choice.
“This nation’s security agencies violated our democracy yesterday. I’m still recovering this morning from the huge shock.
“Our democracy was raped by the DSS, Police, and Military; it was not INEC; it was more like a security agency coup.
“Let’s save the drift into anarchy, let’s save our country and her democracy, there was no election yesterday and we call on the INEC Chairman, Prof. Mahmood Yakubu to cancel the purported results.”