Israeli Prime Minister Benjamin Netanyahu has taken the unprecedented step of condemning Jeremy Corbyn for laying a wreath at a service in memory of the Black September terrorists behind the Munich massacre.

In a rare instance of a foreign head of government condemning a British political leader, Mr Netanyahu tweeted Mr Corbyn's laying of a wreath during the ceremony in Tunis in 2014 "deserves unequivocal condemnation from everyone - left, right and everything in between".

Mr Netanyahu's tweet follows days of claims and counter-claims, as Mr Corbyn's team sought to deny he was at the ceremony to lay a wreath for the Black September but people who were killed in a 1985 Israeli airstrike who are buried in the same cemetery.

Mr Corbyn said he was "present" but he did not "think" he was "actually involved" in the laying of a wreath for the members of Black September.

This is despite photos published in the Daily Mail showing him laying a wreath at their memorial and Mr Corbyn writing an article at the time saying the memorial was for people killed by Mossad in Paris in the early 1990s, which includes Black September members, the group that kidnapped and killed 11 Israelis at the 1972 Olympic Games.

Two widows, who lost their husbands in the massacre, condemned Mr Corbyn, saying he "has no place in politics, or in decent, humane society when he is driven by one-sided hate and vengefulness".

His laying of a wreath has also been contrasted with his failure to take up an invite to visit Yad Vashem, which he has not 

Mr Corbyn responded to Mr Netanyahu, saying his claims were "false" but did not say how.

He added: "What deserves unequivocal condemnation is the killing of over 160 Palestinian protestors in Gaza by Israeli forces since March, including dozens of children."

Mark Regev, Israel's ambassador in London, tweeted the response to the Munich massacre from Harold Wilson, who was Labour leader at the time.

"There are no words adequate to express the sense of outrage at so grievous and calculated an act of terrorism," Mr Wilson said in a statement at the time.