Jet Airways suspended all operations last month.

Days after former Jet Airways chairman Naresh Goyal and wife Anita Goyal were dramatically taken off an aircraft to stop them from leaving the country, NDTV has learnt that two separate investigations have been launched against former promoters of the crisis-hit airline - including the couple - to find out if there was any financial irregularity in the years leading up to its collapse.

The Serious Fraud Investigation Office (SFIO), which functions under the Ministry of Corporate Affairs, and the Enforcement Directorate (ED), which reports to the Finance Ministry, have initiated the probes.

While the SFIO is investigating accusations against the then promoters of Jet Airways of siphoning off funds, the ED, according to sources, has initiated a preliminary enquiry into allegations that foreign investment rules were violated when Abu Dhabi's Etihad Airways invested $150 million for a 50.1 per cent stake in Jet Privilege Private Ltd, a loyalty and rewards management company formed in 2012 as a subsidiary of Jet Airways. In both the probes, the role of Naresh Goyal is primarily being looked into, sources said.

Naresh Goyal stepped down from the Jet Airways board in March.

"No ECIR (Enforcement Case Information Report - the equivalent of an FIR in a criminal case) has been registered yet in this matter, only a preliminary enquiry has been started," a senior Enforcement Directorate official told NDTV.

"Unlike other issues, in cases relating to FDI (Foreign Direct Investment) violation, ED has original jurisdiction and can initiate a probe by ourselves and need not be relying on other agencies' FIRs," he said.

Naresh Goyal and his wife Anita Goyal were stopped from leaving India on Saturday at the Mumbai airport after they had already boarded a flight for London via Dubai.

According to sources, the reason Goyals were not stopped at immigration was because the SFIO's lookout circular - a notice sent to all airports and ports - asked only to be informed about their travel. It was after the agency received the input about their travel from the Bureau of Immigration that the SFIO swiftly managed to change the notice asking "prevent the accused/subject from leaving the country".

By this time, the Emirates plane carrying Goyals was on the taxiway and air traffic controllers managed to call back the plane following which the couple were taken off and informed about the notice against them.

Once one of India's largest carriers, Jet was forced to ground all flights last month after running out of money and failing to secure funds, crippled by mounting losses as it attempted to compete with low-cost rivals.

The carrier is saddled with some $1.2 billion in bank debt, and the Goyals stepped down from the airline's board in March amid the crisis.

Amid speculation over its total financial collapse, Jet Airways had said that it had complied with all regulations. Naresh and Anita Goyal did not comment on the reports at the time.