The CBI had earlier said that the former IAF chief has admitted to have financial interest in three companies-Banshi, Anuras and Shavan - involved in the controversial Rs. 3,600 crore chopper deal.
The agency further stated that Tyagi has accepted that he met COO of Finmeccanica Zapa in 2005 in India.
The CBI also said the former IAF chief and his wife are the owners of the three companies in addition to a fourth company- Meghanshu - and added that all the four companies are based in Noida.
The agency had registered a case against Tyagi along with 13 others including his cousins and European middlemen.
The allegation against the former IAF chief was that he reduced flying ceiling of the helicopter from 6,000m to 4,500m (15,000ft) which made AgustaWestland helicopters eligible in the race for the deal.
The IAF chief has, however, denied all the allegations being levelled against him as false.
It is alleged by Italian prosecutors that bribes to fix the deal were paid through middlemen and routed through a consultancy contract between AgustaWestland and companies owned by middlemen