Pakistan legspinner Danish Kaneria has been refused "clearance" by the PCB to join the Test squad for the series against South Africa in the UAE.

Kaneria was due to fly to Dubai early on Sunday morning as one of a group of five players but he was called by a board official just before he was due to leave for the airport and informed that he could not go. Mohammad Sami, Azhar Ali, Taufeeq Umar and Mohammad Yousuf all left to join the squad.

"Danish has not been given clearance by the board," Zakir Khan, the PCB's director of cricket international, told ESPNcricinfo. No other reason was given. Ijaz Butt, the PCB chairman, and other officials were unavailable for comment.

The last-minute development is bound to fuel speculation over the reasons of the sudden u-turn. Kaneria was selected in the original squad announced in October and, as chief selector Mohsin Khan repeatedly stressed that no player will be selected unless he was cleared by the chairman, it must be assumed that Kaneria was cleared initially.

Kaneria was also part of the training camp the team had before the departure for the UAE. He has since played in the Quaid-e-Azam trophy as well, taking 18 wickets in two games for Habib Bank Limited. He last played for Pakistan in the Trent Bridge Test against England in August, after which he was dropped. Kaneria had played 61 Tests and is the country's most successful spinner with 261 wickets.

It is not clear whether the decision has anything to do with the PCB's attempts - compelled by the ICC's warning last month - to put its house in order and tighten up against corruption. Kaneria was the subject of a criminal investigation through the summer by Essex police over allegations that he was involved in spot-fixing during a county game. The investigations had begun in May but Kaneria was cleared by police in September.

Osman Samiuddin is Pakistan editor of Cricinfo