She has branded the police investigation against her "a vanity case" after being found not guilty of fiddling €3800 in European parliamentary expenses claims and laundering the cash.
Sinclaire, who represented the West Midlands region until 2014, had denied deliberately submitting 10 dishonest claims for travel.
The 47-year-old said that instead some expenses had been "deliberately corrupted" by her former office assistant.
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After being cleared, she criticised police handling of the inquiry, saying the 10 incorrect claims upon which the prosecution case rested were now seven years old, dating to October 2009.
Sinclaire said: "In times of police cutbacks I find it incredible that on the say-so of one embittered man, West Midlands police spent, I believe, in the region of €1.78m chasing a vanity case of €3800."
The former MEP added: "I was arrested more than four years ago, and that event had blighted my political career and, more importantly, my life.
"I now welcome the opportunity to move forward."
A West Midlands police spokesperson said: "This long, complex inquiry has been investigated in a diligent and professional manner. It resulted in extensive evidence being presented to the Crown Prosecution Service which they accepted as significant enough to charge Nikki Sinclaire.
"Our criminal justice system quite rightly demands a very high standard of proof and we acknowledge the verdict from the jury."
The force defended its handling of a "diligent and professional" investigation, but declined to say how much the inquiry cost.
Birmingham Crown Court had heard there had been an atmosphere of "hostility" between Sinclaire and outgoing Ukip leader, Nigel Farage, and that her former aide had passed information about her to the party.
Jurors spent just three and a half hours in deliberations before clearing Sinclaire of both charges.
She had always admitted the claims on which the crown's case rested were in "error", but told jurors she "paid no attention" to travel expenses as it was her office staff's job.
She told the jury: "I was negligent - I am embarrassed about it." However, she denied any deliberate wrongdoing.
Sinclaire said the expenses were either mistakes by staff, or in at least one claim were "deliberately corrupted" by her former aide.
Jurors also heard of several examples where she could have made genuine claims, including parliamentary trips to Cyprus and Cuba, and staff costs, which were never submitted, and effectively left her out of pocket.
Sinclaire alleged that compiling expenses claims was dealt with by her Birmingham office staff, while she just copied information supplied by her assistants on to the forms before signing them off.
The jury had also heard about a background of Ukip infighting and how Sinclaire lost the party whip as a result of internal disagreements in January 2010.
She said that her subsequent arrest by West Midlands police blocked her from re-joining Ukip. She then failed to get re-elected in 2014.