Activists on Tuesday accused former European Commission president Jose Manuel Barroso of breaking his pledge not to lobby the EU on behalf of his employer Goldman Sachs.
A coalition of NGOs accused the former Portuguese prime minister of meeting with a vice-president of the current EU executive, Finland's Jyrki Katainen, in a hotel last year.
"This information confirms that Mr. Barroso has not kept his commitment to not lobby on behalf of Goldman Sachs," said Alter-EU, a coalition of NGOs specialising in the fight against corruption, in an open letter to the secretary general of the Commission, Alexander Italianer.
Katainen, in a letter to activists, confirmed the meeting and insisted it was mainly devoted to "questions of defence and trade".
"Twenty-four hours after this meeting, vice-president Katainen published this meeting (in the EU transparency register) according to the procedure," said Commission spokesman Margaritis Schinas at a daily briefing.
He "religiously followed the legal parameters that apply," said Schinas, refusing any further comment.
Goldman Sachs said in a statement that Barroso "has from the beginning of his time with us recused himself from representing the firm with any interactions with EU officials.
"Any such meetings are in his personal capacity built over a long career of public service."
Barroso's hiring in 2016 by the US investment bank, after 10 years at the head of the Commission from 2004 to 2014, sparked a huge media firestorm with then French president Francois Hollande saying it was "unacceptable".
After a probe, an EU ethics committee cleared Barroso, who waited the compulsory 18 months, of breaching ethics rules but criticised his "judgement" for taking the Goldman job.
Barroso had insisted in a letter to the head of the European Commission Jean-Claude Juncker that "I have not been hired to lobby for Goldman Sachs and I do not intend to do so".
The meeting with Katainen took place on 25 October 2017 in a Brussels hotel.
Alter-EU said it considered the sitdown between Barroso and the former the Finnish premier to be a lobbying activity and that the case must again be examined by the ethics committee.
"The body should this time conduct a more thorough investigation of the role of Barroso with Goldman Sachs and assess whether the former president has misled President Juncker," the activists said.