Speaking to reporters at the Assembly, the Sinn Féin MLA said Gerry Adams has been the single most important person in building peace in Ireland.
"I view his arrest as a deliberate attempt to influence the outcome of the elections due to take place all over this island in three weeks," he said.
The Mid-Ulster representative added that the allegations against Gerry Adams in relation to the death of Jean McConville have come from elements within society who are hostile to the Peace Process and wish to see it collapse.
Martin McGuinness also added that he has every confidence that Gerry Adams will continue to lead Sinn Féin through the upcoming election campaign.
Timing of Gerry Adams's arrest 'politically motivated' during election campaign
The timing of the arrest of Sinn Féin President Gerry Adams TD by the PSNI investigating the abduction and killing of Jean McConville in Belfast in 1972 is politically motivated and designed to damage Sinn Féin's all-Ireland election campaign, Mary Lou McDonald says.
Gerry Adams, the former MP for West Belfast, presented himself voluntarily to the PSNI in Antrim on Wednesday evening and he was subsequently arrested for questioning.
Elections take place North and South in three weeks. Gerry Adams's arrest comes days after opinion polls showed a huge surge of support for Sinn Féin across Ireland and Gerry Adams as the most popular party leader amongst the public.
Speaking before travelling from the Dáil via his constituency office in Dundalk on Wednesday evening, Louth TD Gerry Adams said:
"Last month I said that I was available to meet the PSNI about the Jean McConville case. While I have concerns about the timing, I am voluntarily meeting with the PSNI this evening.
"As a republican leader I have never shirked my responsibility to build the peace. This includes dealing with the difficult issue of victims and their families.
"Insofar as it is possible, I have worked to bring closure to victims and their families who have contacted me. Even though they may not agree, this includes the family of Jean McConville.
"I believe that the killing of Jean McConville and the secret burial of her body was wrong and a grievous injustice to her and her family.
"Well-publicised, malicious allegations have been made against me. I reject these.
"While I have never disassociated myself from the IRA and I never will, I am innocent of any part in the abduction, killing or burial of Mrs McConville.
"Sinn Féin has signed up to the Haass proposals for dealing with the past. While I also respect the right of families if they wish to seek legal redress, there remains a huge onus on the two governments and the political parties to face up to all these issues and to agree a victim-centred process which does this."
Sinn Féin deputy leader Mary Lou McDonald reiterated that Gerry Adams said last month that he was available to meet the PSNI about the Jean McConville case and he has always denied allegations by openly hostile critics of the Peace Process and Sinn Féin.
"Gerry Adams is right to confront this issue," Mary Lou McDonald said. "There has been a concerted and malicious effort to link Gerry Adams to this case for some considerable time.
"He has consistently and forthrightly rejected any suggestion that he had any part in what happened to Jean McConville 42 years ago or that he has any information about these dreadful events.
"I believe the timing of this latest decision by the PSNI is politically motivated and designed to damage Gerry Adams and Sinn Fein.
"It is Sinn Féin's view that legacy issues and dealing with the past, including past conflict events, are best addressed through an independent, international, truth recovery process.
"In the absence of that, we have agreed to and are seeking the implementation of the Haass compromise proposals. These include the right of families to choose whether to pursue legal action or to seek maximum truth recovery."
International calls for release of Gerry Adams
International pressure is growing for the release of Gerry Adams following his politically-motivated arrest by the PSNI.
Greece - Protesters from the SYRIZA political coalition, the second-largest political group in the Greek parliament, demonstrated outside the British Embassy in Athens where party leader and candidate for President of the EU Commission, Alexis Tsipras, called for the immediate and unconditional release of the imprisoned TD.
USA - Republican Congressman Peter King told NBC News that the political implications of Gerry Adams' arrest will cause growing tension in the North. He added that he has known Gerry Adams for 30 years and described him as "always truthful" and "more instrumental than anyone" in bringing peace to Ireland.
Democratic Congressman Richard E. Neal told the Boston Globe that the arrest is "one of those unsettling moments" and said he was suspicious of the timing, which comes just before elections. "It all seems pretty murky," he said.
Basque Country - Basque pro-Independence party Sortu, which makes up the Basque Parliament's opposition EH Bildu coalition, described the arrest as an attack on the Peace Process and "an attempt stop the unstoppable advance of republicanism in the whole island of Ireland."
Catalonia - The Young Republican Left of Catalonia (JERC), the youth wing of Esquerra, the second-largest political grouping in Catalonia, described the arrest as "an attempt to discredit him and his political organization, Sinn Fein, in a moment in which the local and European elections seem to be very favorable."
Italy - Banners calling for the release of Gerry Adams were carried by left-wing demonstrators during the annual May Day march in the city of Milan.
Martin McGuinness also added that he has every confidence that Gerry Adams will continue to lead Sinn Féin through the upcoming election campaign.
Comment: Ah, the plasticity of democracy!
Your opponent is likely to win more votes than you'd like? No problem, just arrest him!
Your client regime is falling because the voters want something else? No problem, cancel the elections!
Your candidate lost by a narrow margin? No problem, saturate the media with lies about unsound vote-counting procedures, then have the court you own rule in his favor!
Someday, soon, (we can hope), people in the West are going to realize this whole democracy thing is a complete and utter farce.