The former Edo State governor made this declaration while speaking at the campaign rally of President Muhammadu Buhari in Benin, Edo capital on Thursday.
While welcoming politicians who joined the APC after recently dumping the PDP, Oshiomhole said they'll help Buhari to defeat their former party.
"I'm told that there are a lot of very senior people from PDP who have decided to join forces with President Buhari to take the broom to sweep away PDP," he said.
While reading out the names of the defectors to the rally crowd, Oshiomhole translated the name of one of them to mean "I don do bad [I have done (something) bad]".
He then proceeded to say all sins are forgiven once they teamed up with the ruling party.
"And, in fact, once you've joined APC, all your sins are forgiven," he announced.
While Oshiomhole's words appeared to have been said casually, it's bound to fuel long-standing allegations that the ruling party is a haven for opposition politicians trying to escape scrutiny for wrongdoing.
President Buhari's anti-corruption fight has been dogged by allegations that he relentlessly persecutes opposition candidates while shielding members of his party from the law.
At the rally, Oshiomhole told the crowd that the PDP has nothing to offer Nigerians and must not be allowed back into power to loot the nation's wealth.
In a short speech, Buhari urged Nigerians to give him another four years in office to continue to set a great course for the nation's future.
The February 16 presidential election is expected to be a keen contest between him and PDP candidate, Atiku Abubakar, a former Vice President.