Peer was subject to protests at a tournament in New Zealand last month
Israeli player Shahar Peer has been refused a visa to take part in the Dubai Tennis Championships.
Peer was scheduled to play 15th seed Anna Chakvetadze of Russia in the $2m event on Monday.
But the WTA Tour said Peer was denied entry into the United Arab Emirates for the tournament, which features all the world's top-10 ranked women's players.
UAE officials have not given a reason for the move, but the country does not have diplomatic relations with Israel.
The only Israelis usually allowed into the UAE do so under dual nationality, and the player's brother and spokesman Shlomi Peer confirmed she had been denied a visa.
WTA chief executive Larry Scott said the women's tour was "deeply disappointed" by the decision.
It's not acceptable. I think sport should be above issues like that to do with religion and wars
"Ms Peer has earned the right to play in the tournament and it's regrettable that the UAE is denying her this right," he said.
"Ms Peer and her family are obviously extremely upset and disappointed by the decision of the UAE and its impact on her personally and professionally."
Scott said the WTA would "review appropriate future actions with regard to the future of the Dubai tournament".
"No host country should deny a player the right to compete in a tournament for which she has qualified by ranking," he added.
Fellow players also voiced their disappointment at the news.
"It's not acceptable," said Amelie Mauresmo after clinching the Paris Open title on Sunday.
"I think sport should be above issues like that to do with religion and wars and whatever. I'm surprised."
And Russia's Olympic champion Elena Dementieva, the runner-up to Mauresmo in Paris, said: "I feel very sorry for her. She's a very good girl and very sensitive.
"I played her in Auckland and there was some kind of demonstration during the match.
It's very unfortunate, I feel very sorry for her
"I just feel sad for her. She really cares about what's going on between Israel and Palestine and it's just a very tough situation.
"I think the tour takes it seriously and I wish she could play in Dubai."
Speaking in Dubai, former world number one Ana Ivanovic of Serbia said: "It's very unfortunate, I feel very sorry for her.
"Shahar is a friend of mine and I feel sorry she's not here. It's always a pity to mix politics and sport. But the WTA is looking into it."
World number two, Dinara Safina, added: "It's pretty disappointing she's not playing here. She's a great player and a great athlete.
"I hope she will have many more chances. I think the WTA is doing its best for them."
World number 48 Peer faced protests over Israel's military offensive in Gaza at the ASB Classic in Auckland last month from around 20 people who called on her to withdraw from the tournament.
The 21-year-old was beaten 6-1 6-4 by number one seed Vera Zvonereva of Russia in the semi-finals of the Pattaya Open in Thailand on Saturday.