Do investors trust Volkswagen to investigate itself and lay the appropriate blame? Not these three groups.

With the financial damage of the diesel emissions scandal now clear, three large investor groups are calling for accountability and the launch of an independent investigation, Reuters reports.

After the diesel hit the fan, Volkswagen set up a committee to investigate the scandal and hired law firm Jones Day to look into the issue and craft a report. That report comes out later this year.

Nice, but not good enough, say the groups, who worry the investigations won’t dig deep enough or be as accountable as some would like.

Made up of German investor group DSW, Belgian firm Deminor (which manages New York City’s pension fund) and UK-based Hermes EOS, the players want Volkswagen shareholders to be able to vote on a new inquiry at the automaker’s June 22 annual general meeting.

“When you have an independent investigation you can be sure that the findings will be publicized,” DSW spokesman Juergen Kurz told Reuters. “With internal investigations you do not know whether everything has been made transparent.”

Deminor called out the automaker’s scandal committee for only looking for “serious and manifest breaches,” which means the probe would overlook lesser transgressions among management.

Hermes is of the same mind, stating that the firm worries about the “potential liability of the members of the management and supervisory boards.”

Earlier this month, Volkswagen’s supervisory board essentially cleared management of wrongdoing in the scandal in preparation for the June AGM.

Despite the ongoing investigation by Jones Day, nothing serious cropped up in their findings, the board claimed. They’re recommending that shareholders ratify management’s 2015 decisions, an action required by German law.

Representatives from Hermes, Deminor and DSW might have something to say about that.