DUBAI The Umpire Decision Review System (UDRS), which became official from October 1 after several trials were opposed by the Indian cricket board, it is learnt here. According to highly placed sources in the ICC, the Indian cricket board, possibly on Indian players request , has expressed its reservation over the system and has asked certain clarification. The system, which was to be implemented during the three-match Test series between India and Sri Lanka beginning in Ahmedabad on Monday, may not be used in the current series. The UDRS was first trialled during Indias Test tour of Sri Lanka last year, when almost every Sri Lankan challenge bore fruit while a majority of the Indian challenges came to nought. At that point, each team was allowed three unsuccessful challenges per innings. Consequently, to cut down on frivolous challenges and to prevent unnecessary delays, the number of unsuccessful challenges permitted was reduced to two. We have received a letter from the BCCI expressing their concern over the system. We are trying to sort out the matter and if it does not work, it may not be used in this series, a source said. However, the source further added, Both Pakistan Cricket Board (PCB) and New Zealand Cricket (NZC) have agreed in principle to have this system in place for the forthcoming three Tests series in New Zealand. The PCB is hosting its home series in New Zealand later this month. Interestingly, this is not the first instance where the BCCI, at its players request, has opposed the ICCs decision which was agreed in principle. It may be recalled here that the wheraeabouts clause of WADA was also opposed in this fashion and no consensus on the issue has been reached yet. In the UDRS, players have the option to challenge the umpires decisions for a specific number of times per innings.