The chairman of the Zionist Federation has said the organisation does not know why X Factor winner Alexandra Burke pulled out of tonight's Israel’s 65 concert.

The singer, who performed at Jewish weddings with the Gilev Showband before her rise to fame in 2008, was due to perform at the Yom Ha’atzmaut event at Wembley Arena.

But the ZF emailed supporters on Monday to say she would not appear and had been replaced by Stacey Solomon.

No reason was given for Ms Burke's withdrawal, and her spokesman has not responded to requests for an explanation.

Her absence led anti-Israel activists to claim she may have withdrawn for political reasons or in support of boycott, divestment and sanctions against Israel.

But ZF chairman Paul Charney said: "The BDS campaigners can claim what they like. We don't fully understand the reasons why Alexandra Burke has pulled out.

"We are not going to deal with Alexandra Burke today. When the event is over we can find out why this has happened.

"There were problems - that's all they told us. Alexandra or her management made the decision. We do not know how or why.

"It was very recent and we took the decision to move on with the party and have the big bash and then after we can find out and have a frank discussion.

"We will try to understand the reasons why she pulled out. Maybe it was BDS, maybe there are other reasons."

The JC understands hoax press releases have been sent out claiming Israeli pop star Ishtar, lead singer of Alabina, has also pulled out, citing security fears.

But the ZF confirmed she would appear at the concert, alongside other performers including Britain's Got Talent dance troup Spellbound and Chico from the Gipsy Kings.