Mr Dwyer died after being targeted by an anti-terrorist Bolivian police force in April 2009.
The Oireachtas group’s chairman, Pat Breen, said it was clear the 24-year-old was “unarmed and executed” when he was shot.
He said the committee believed there needed to be “a full independent international investigation into the events that led to the death” of the Tipperary native.
He added that the family believe they have evidence from an independent forensic technical report that — along with a document by state pathologist Marie Cassidy — shows “without any doubt” their son was unarmed when he was shot.
The family has also made a submission to the UN Special Rapporteur on Extrajudicial Summary or Arbitrary Executions, seeking a full investigation.
Mr Dwyer was one of three people shot dead over an alleged plot to assassinate President Evo Morales.
In January, WikiLeaks released a diplomatic cable from the US embassy in La Paz which quoted a source as saying the group Mr Dwyer was with had been hired to mount a phoney terrorist campaign.
This would then be used to justify the persecution of Mr Morales’s opponents, it was claimed.
Investigators later claimed to have found emails linking one of the men shot with Mr Dwyer to Istvan Belovai, a former Hungarian military intelligence officer who defected to the US in 1990 and later became a CIA agent. US diplomats said this was a hoax.