Demonstrators treat Palestinian journalist Yasser Murtaja, who later died from his wounds, after he was shot by Israeli security forces during protests along the Gaza-Israel border on April 6, 2018

A Palestinian reporter killed last week by Israeli fire was detained and beaten by Hamas security forces in 2015, a global journalist body said Wednesday, after Israel accused him of being a member of the Islamist group.

Yasser Murtaja was shot dead during clashes on the Gaza border Friday while, witnesses said, wearing a press vest, leading to criticism of Israel's open-fire policy.

Israel's Defence Minister Avigdor Lieberman on Tuesday accused the journalist of being an active member of Hamas, Gaza's Islamist rulers, with which the Jewish state has fought three wars in a decade.

Lieberman claimed the 30-year-old had received a salary since 2011 and held a rank similar to captain in Hamas's armed wing, but provided no evidence for the claims.

A case file from the International Federation of Journalists (IFJ) documented how Murtaja was detained and beaten by Hamas security forces in 2015 while filming.

The file, seen by AFP, said Murtaja and three other colleagues were filming the demolition of a home near the Israeli border when a man demanded to see their documents.

After they refused, a jeep belonging to the Hamas security forces arrived and "pulled the photographer Yasser Murtaja into their jeep without explaining what was going on."

It said inside the van he was beaten by Hamas police, leading to his eventual hospitalisation. After an interrogation, his photographs were eventually seized.

Murtaja and the other journalists were interviewed by an IFJ researcher at the time, the file said.

IFJ general secretary Anthony Bellanger accused Lieberman of a cover-up.

"It is clear that having murdered a journalist the Israeli defence minister is more interested in spouting propaganda and engaging in a cover-up than in carrying out a thorough and transparent investigation and bringing Yasser´s killers to justice," he said in a statement.

Israeli forces have killed 31 Palestinians and wounded hundreds others since March 30 as mass protests along the Gaza border have led to clashes.

There have been no Israeli casualties.

Israel says its forces have opened fire to stop attempts to damage the fence, infiltrations, bids to carry out attacks and at those seeking to harm soldiers.