Lawmakers from nine countries, in London for an extraordinary joint investigation, chastised Facebook CEO Mark Zuckerberg on Tuesday for failing to appear before them to answer questions on how the platform has been used to spread disinformation and fake news.

Instead of Zuckerberg – for whom a conspicuously empty chair was set – the legislators grilled Richard Allan, Facebook’s vice president of policy solutions. Allan acknowledged that recent scandals had undermined trust in the social network, including the leak of personal data to now-defunct Cambridge Analytica and the revelation that Facebook had hired a firm called Definers to combat allegations against it by suggesting financier George Soros was behind the negative press.

“I’m not going to disagree with you that we’ve damaged public trust through some of the actions we’ve taken,” Allan, a former member of the British Parliament, told the group of international lawmakers assembled in a British parliamentary hearing room.

He said that Zuckerberg “was not personally responsible for the hiring” of Definers and that the Facebook co-founder “has given instructions for us now as a team to look very carefully at all the relationships with different external agencies to make sure that we behave.”

But many of Allan’s interlocutors were less than satisfied with Allan’s answers – and with his boss’s no-show.

“We’re asking your company to be accountable when issues come up such as genocide, such as misinformation. We don’t know that Mr. Zuckerberg is looking into it because he has refused to show up to speak to parliamentarians from around the world,” said Canadian lawmaker Charles Angus. “I put it to you have lost the trust of the international community to self-police and that we have to start looking at a method of holding you and your company accountable.”

Besides Britain and Canada, the two dozen representatives assembled in London hailed from Argentina, Belgium, Brazil, France, Ireland, Latvia and Singapore, countries with a combined population of about 450 million. The gathering was organized by the British Parliament’s committee on media and culture.

British lawmakers have been particularly critical of Facebook and Zuckerberg, and have repeatedly called on him to appear before them. Zuckerberg has declined, but did answer questions back in May in an appearance before the European Parliament.

Allan said that Facebook now employed thousands of people to monitor content on the site and that shutting down fake accounts remained “an ongoing battle.”

“The battle’s not over, but…we’ve started to make inroads,” he said.

The convening of the international parliamentary inquiry came just days after it emerged that British lawmakers had used a rarely wielded authority to seize Facebook documents from an American businessman who was in London on a work trip. The man is an executive with the software firm Six4Three, which is in legal proceedings against Facebook.

Facebook has demanded the documents’ return. But Damian Collins, the chair of the parliamentary committee on media and culture, said that they were relevant to the inquiry on disinformation and data security – and that he could make their contents public if he chose.

“We have asked many questions of Facebook about its policies on sharing user data with developers, how these have been enforced, and how the company identifies activity by bad actors,” Collins wrote in a letter to Allan. “We are also interested to know whether the policies of Facebook…are consistent with the public statements the company has made on the same issues.”