A high-profile Norwegian doctor who has said the September 11 terrorists were justified in their attack is now treating patients in Gaza and is being accused of presenting "hard-core propaganda" to TV interviewers in his telling of the conflict between Hamas and Israel.

Dr. Mads Gilbert has become an unofficial advocate of the Palestinian cause, his critics say.

International media reports, including those from the BBC, CBS, CNN and FOX’s sister station Sky News, present Gilbert as an ordinary doctor.

But a look at his record shows that Gilbert, 61, is a political activist and member of the Norwegian Maoist "Red" party, and he has been involved in solidarity work for the Palestinians since the 1970s. He has criticized the international aid organization Doctors Without Borders for refusing to take sides in conflicts.

Gilbert volunteers at the Al-Shifa Hospital in Gaza with the Norwegian Aid Committee (NORWAC), an aid organization funded by the Norwegian government, and he has been interviewed by the media on a variety of issues. Israeli government officials have said Hamas hides weapons in the hospital where Gilbert works.

Click here to see a video of Gilbert at Al-Shifa Hospital.

NGO Monitor, an Israeli human rights watchdog group, says Gilbert presents one-sided criticism of Israel to the media and has accused Israel of deliberately targeting civilians in its Gaza offensive to stop Hamas from firing rockets into Israel.

In addition to being supportive of the terrorist organization Hamas, Gilbert has voiced support for the Sept. 11, 2001, attacks on the World Trade Center and the Pentagon.

"The attack on New York did not come as a surprise after the policy that the West has led during the last decades," Gilbert told the Norwegian newspaper Dagbladet on Sept. 30, 2001. "The oppressed also have a moral right to attack the USA with any weapon they can come up with."

When asked if he supported a terror attack on the U.S., Gilbert said, "Terror is a bad weapon but the answer is yes within the context which I have mentioned."

Gerald Steinberg, executive director of NGO Monitor, said Gilbert's characterization of the situation in Gaza is "in the form of incitement of hatred."

"We question the accuracy and the political biases — if they exist — by groups that claim to promote human rights, humanitarian and non-political goals," Steinberg told FOXNews.com. "A doctor is someone who is not supposed to take a political side."

"We found out he justified the 9/11 attacks.… Here's a guy with a radical political background who is being interviewed as if he were a neutral medical observer," Steinberg said.

"He has become an apologist for Hamas, totally violating his obligation as a physician to heal the sick and not contribute to violence."

A representative for Sky News said it has not presented a biased picture of the conflict in Gaza when interviewing Gilbert.

“We are reporting events as they happen and interviewing all of the protagonists and a wide range of commentators on the situation," the network said in a statement.

"Dr. Gilbert is a working doctor in Gaza interviewed by the international news agencies in Gaza. A short interview clip with him has been included in one of our reports. Sky News has consistently reported on the Hamas rocket attacks into Israel, given extensive context and background to the dispute and interviewed the Israeli President live on air for 15 minutes."

The BBC did not respond to a request for comment.

Gilbert told FOXNews.com that he is neither anti-Israeli nor anti-American.

"I did my Ph.D. research in the United States at the University of Iowa in Iowa City," Gilbert said. "I have hundreds of American friends and I have many, many Jewish friends.

"I have nothing against the people of Israel. I have nothing against the Jews. In fact, I think that one of the worst things that happened in history was the Holocaust."

But Gilbert said he and NORWAC do not hide their pro-Palestinian bias in the Hamas-Israel conflict.

"We support the Palestinian people, and that's absolutely no secret that we have been supporting the Palestinian people for many years," Gilbert said. "We have been working tirelessly to improve the medical conditions through systematic training and teaching....

"I do not support the wall on the West Bank and I do not support the siege of Gaza," he said.

"This is very simple. If that is biased, so be it. Call me biased."

Steinberg said Gilbert's partisanship violates his ethical code.

"By justifying terror, supporting Hamas and fueling the conflict, NORWAC and Mads Gilbert have violated the Hippocratic Oath — 'first, do no harm'," he said.

The Hippocratic Oath states: "In every house where I come I will enter only for the good of my patients, keeping myself far from all intentional ill-doing."

But George Annas, a professor of medical ethics at The School of Public Health at Boston University, said Gilbert's political stance does not violate ethical codes.

"I think its fine for doctors to have political affiliations as long as they make them known. It really doesn't get to be a medical ethics issue unless you get some patients involved," Annas said.

Problems might arise, Annas said, "if he has wounded and sick patients and has been taking time away to do interviews and people are dying."