SEBI sources said the role of BSE stock brokers and other "large" investors, including that of Big Bull Harshad Mehta, will come under the market watchdog's scrutiny.

SEBI chairman DR Mehta is expected to take a final decision on the matter in the next few days.

The SEBI move on Global Trust follows the board's recent decision to go in for similar investigations into Videocon, BPL and Sterlite scrips, which are also widely believed to be Harshad Mehta favourites. Mehta and his associates, who include a clutch of brokers, are also expected to have incurred losses running into hundreds of crores as the market crashed sharply in the recent past. Sources said this time the SEBI was determined to complete investigations in a given time-frame and to trace the actual buyer behind these scrips. The actual buyers often route the purchase orders through a string of `front' outfitsso that tracing them becomes a difficult task. SEBI may also look into reports that positive information about these companies was leaked to the media selectively to improve market sentiment.

The Global Trust scrip has been on a roller-coaster since February this year. It rose from Rs 41 in mid-February this year to Rs 74 by mid-April. It then came down to Rs 53 around May 15 and after a short rally, which took it to Rs 62 on May 20, the scrip plunged to Rs 37 on June 16.

SEBI is expected to ask Bombay Stock Exchange brokers, who have dealt heavily in the scrip in the last three-four months, to give details of transactions and the names of the clients on whose behalf the scrip was purchased. It is widely believed that Global Trust has been one of Harshad Mehta's favourite scrips along with BPL, Sterlite and Videocon.

The scrip has seen heavy trading in the past two months. The long-purchase position of the scrip on May 5 was 16.71 lakh shares against short-selling position of 79,300 shares. Even inMay-end, the long purchase position was 15 lakh shares against short sale position of 75,500 shares. In less than a month, the long purchase position has come down to 8.79 lakh shares as on June 16 with a short sale position of 31,500 shares.