BRUSSELS (AP) — A top official at the European Union has voiced concern over the potential influence a former president of the bloc's executive arm may have on negotiations related to Britain's exit from the EU, following his summer appointment at Goldman Sachs.

Jose Manuel Barroso, who served two terms as European Commission president, joined Goldman Sachs in July, a move that revived complaints about EU officials taking up lucrative jobs after leaving.

Barroso is understood to be advising the U.S. bank on Brexit.

Emily O'Reilly, who oversees transparency issues, said Tuesday that "this is a significant public interest issue and must be openly and comprehensively addressed."

Barroso respected the mandatory 18-month cooling-off period before joining Goldman Sachs but his move has faced criticism within the EU.