PROVIDENCE, R.I. (WPRI) -- The R.I. Ethics Commission has launched an investigation into allegations of nepotism against Cranston Mayor Kenneth Hopkins, who is currently running for re-election.

The panel voted 6-to-0 to open the probe, which was spurred by an ethics complaint filed earlier this month by John Psilopoulos, who served as a top aide to former Cranston Mayor Allan Fung.

Hopkins, a first-term Republican mayor, told 12 News he welcomed the investigation. But he also blamed state Rep. Barbara Ann Fenton-Fung -- who is Fung's wife and is running against Hopkins in the GOP primary for mayor -- for what he characterized as a politically motivated complaint.

"It's a political shot," Hopkins said. "It's an underhanded shot to attack my ethical behavior and it's unwarranted."

Fenton-Fung shot back, calling the ethics allegation a serious complaint, and "everyone must be held to the same standard."

"What's disheartening as the ethics investigation is launched is the Hopkins team continues with their ethical lapses and flaunting of the rules that ensure public trust," Fenton-Fung said in a statement.

As Target 12 first reported, the complaint accuses Hopkins of nepotism in the hiring and promotion of the mayor's son-in-law, Jacob Shackleford, who is a Cranston Fire Department rescue lieutenant. Psilopoulos alleges Shackleford was hired about seven months ago and then promoted earlier this year "after another firefighter who had received a promotion earlier rescinded it after only several weeks."

The ethics panel will now look into whether the allegations are true, and whether they violated the state ethics code. The law prohibits elected officials from hiring or supervising family members if they stand to benefit either financially or by employment.

Hopkins did not seek an ethics decision before the city hired and promoted Shackleford.

After taking the vote, chairperson Marisa Quinn highlighted that the investigation "should not be construed as an opinion regarding the truth and facts alleged in the complaint."

"It's merely a vote to conduct an investigation into the allegations that are raised," she added.

Erica Ricci contributed to this report.