The birther conspiracy theory still hasn't died.

After a six-month investigation, America's self-proclaimed toughest sheriff suggested Thursday that President Barack Obama's birth certificate and selective service registration cards are fakes.

Maricopa County Sheriff Joe Arpaio told reporters at a Phoenix news conference that he and his Cold Case Posse believe probable cause exists indicating that forgery and fraud may have been committed when the president presented a birth certificate last April, according to CBS News.

Based on all of the evidence, I cannot in good faith report to you these documents are authentic, Arpaio said, adding that his investigators believe that the long-form birth certificate was manufactured electronically and never existed in paper form.

Birthers Discredited Earlier

The announcement is sure to feed the theories of birthers, who believe that the president was born in Kenya. The controversy reached its height after real estate mogul Donald Trump demanded that Obama present his birth certificate during his short flirtation with running for president. He dropped out of race last year to focus on the Celebrity Apprentice.

Obama's father was born in Kenya, but documents and officials assure that the president was born in Hawaii. The theories were largely debunked after several officials from Hawaii confirmed Obama's birthplace and the White House presented an official birth certificate -- the one examined in Arpaio's investigation -- last April.

The press conference comes as the 79-year-old sheriff, who has a knack for claiming the spotlight, battles in a long-time legal standoff with the Obama administration and runs for a sixth term.

Arpaio, a strong opponent of illegal immigration, is being investigated by a federal grand jury for criminal abuse-of-power allegations  related to his anti-public corruption squad. In a separate probe, the U.S. Justice Department accused Arpaio's office of racially profiling Latinos and threatened to sue him in 2010 if he didn't cooperate, according to The Washington Post.

Despite his differences with the Obama administration, Arpaio insists the investigation wasn't personal.

I'm not going after Obama, Arpaio said, according to The Associated Press. I'm just doing my job. The sheriff said he was compelled to do the investigation after nearly 250 people affiliated with the Arizona Tea Party requested the probe last summer.