Asking Sebi to look afresh into the matter and pass an order in six weeks, the tribunal said the regulator's interim order was passed in "gross violation of the principles of natural justice".
Capital market regulator Sebi, through an interim order in March this year had barred six promoters of Zenith Infotech after charging them of stripping company assets for personal gains.
The tribunal has asked Sebi for "fresh consideration expeditiously and preferably within a period of six weeks, from receiving a copy of this order".
Besides, the appellants have been asked to co-operate with the regulator in expediting the matter.
"We have no hesitation in setting aside the impugned order and remanding the matter to Respondent No 1 (Sebi) for fresh consideration in accordance with law by supplying a copy of the complaint to the appellants in advance and also by deciding the jurisdictional issues raised by the appellants in the present appeal before hand," SAT said.
The Securities Exchange and Board of India (Sebi) had also asked the board of Zenith to provide a bank guarantee of $33.93 million, an amount equivalent to the funds that have been diverted from the company, without using the funds or assets of the firm.
In this case, six promoters -- Chairman Rajkumar Saraf, Managing Director Akash Saraf, Vu Technologies, Zenith Technologies, Devita Saraf and Vijayrani Saraf were barred from the securities market.
Passing the order, the tribunal said: "We are of the considered opinion that the impugned ad-interim ex-parte order dated March 25, 2013 is not sustainable in the eyes of law as it has been passed in gross violation of the principles of natural justice".
No complaint as mentioned in the impugned order has ever been supplied to appellants by giving them an opportunity of hearing in the matter before passing the same, it noted.
According to the tribunal, it is difficult to agree with Sebi counsel Shyam Mehta's contention that an opportunity of hearing was given to the appellants by granting them three weeks' time to reply in the impugned order itself.
"It is settled that if the essentials of justice in the sense of granting opportunity of hearing are ignored in passing an order to the prejudice of a person, the order is a nullity for want of natural justice and no amount of post-decisional hearing can cure the same.
"We, therefore, hold that such a post decisional hearing in the fact and circumstances of the present case is no more than an eyewash," the order said.
Sebi had started a probe into the matter after its Integrated Market Surveillance System alerted on a sudden change in the share price of Zenith Infotech Ltd (ZIL) in late 2011.
In the meantime, Sebi also received complaints of ZIL promoters wilfully hiding some key transactions and financial details and about a default in redemption of certain bonds.
A preliminary inquiry report said ZIL had defaulted on redemption of FCCBs (Foreign Currency Convertible Bonds) despite raising money through the sale of its MSD Division, and the same information was not disclosed to investors.
As news of probable default spread, the stock fell from Rs 190 on September 23, 2011 to Rs 45 on November 30, 2011.
The report had said that from the sale proceeds of MSD Division of ZIL, an amount of $33.93 million was diverted for purposes "that were not even remotely connected" to the shareholders' authorisation for repayment/redemption of FCCBs.
The regulator had said the promoters and directors of the company have been prima facie found to have "stripped the assets of ZIL for the benefit/interest of companies/entities controlled by them in fraudulent and deceitful manner"