U.K. Labour Party leader Jeremy Corbyn attended a conference with Hamas terrorists in Doha in 2012, according to a report by The Telegraph on Sunday.

Hamas political bureau chief Khaled Mashaal, who is on the United Kingdom’s sanction list, was just one of the terrorist officials in attendance at the Qatar conference.

Another was Hudam Badran, the former leader of Hamas’s military wing. Under Badran’s leadership, the terrorist group carried out several terrorist attacks during the Second Intifada, including the 2001 suicide bombings at a Sbarro pizzeria in Jerusalem that killed 15 people and at the Dolphinarium nightclub in Tel Aviv that killed 21.

Another terrorist in attendance was Abdul Adiz Umar, who was given seven life sentences for his part in the 2003 bombing of a Jerusalem cafe that killed seven.

Both Badran and Umar were released from prison in 2011 as part of the prisoner-exchange deal to bring back Israel Defense Forces’s soldier Gilad Shalit. In a piece in the United Kingdom’s Morning Star after the conference, Corbyn wrote that the two were freed in return for Shalit, and called their contribution to the conference “fascinating and electrifying.”

In a video of the conference posted by The Telegraph, Badran is seen saying, “The nakba [‘catastrophe,’ the Arabic term used for the displacement of Palestinian refugees after Israel’s establishment] that made us refugees took place via force, and the return will only be viable through military and armed resistance and nothing else.”

A spokesman for Corbyn told The Telegraph that the Labour leader “has a long and principled record of solidarity with the Palestinian people and engaging with actors in the conflict to support peace and justice in the Middle East. That is the right thing to do.”

At the conference, Corbyn also voiced his support for the leader of the Islamic Movement’s Northern Branch, Sheikh Raed Salah, who was being faced with deportation from the United Kingdom for engaging in hate speech at the time.

Meanwhile, a video posted to Facebook last week shows Corbyn calling the BDS movement “part and parcel of a legal process that has to be adopted” against Israel.

Corbyn had previously said that while he supports a boycott of produce from Israeli settlements in the West Bank, he opposes a blanket boycott of Israel.

In footage taken of the 2015 Belfast conference, Corbyn can be seen asking if the panel can “give hope to the people of Palestine by supporting the movement for boycott, divestment and sanctions against Israel.”

He then said, “I think the boycott campaign, divestment campaign is part and parcel of a legal process that has to be adopted. … I believe that sanctions against Israel, because of its breach of the trade agreement, are the appropriate way of promoting [the] peace process.”

The video was published by Sinn Fein, a radical Irish nationalist party with strong ties to the Palestinians.

In December, a spokesman for Corbyn told The Guardian that the leader “doesn’t support BDS. He does support targeted action aimed at illegal settlements and occupied territories.”