2G Scam trial begins in Delhi
The trial in India's biggest corruption scandal began in Delhi yesterday with the questioning of the first witnesses.
The scandal involves the alleged selling of mobile phone frequency licences for a fraction of their value.
Former telecoms minister A Raja and MP Kanimozhi are among 14 people from telecoms firms or government who have been charged. All deny any wrongdoing.
Auditors allege the mis-selling of the licences cost the exchequer nearly $40bn in lost revenue.
The BBC's Sanjoy Majumder in Delhi says the scandal has gripped the country and deeply embarrassed the government.
Last month, the federal Central Bureau of Investigation (CBI) framed charges including criminal conspiracy, forgery, accepting bribes and misuse of office.
The trial, in a special CBI court in the Indian capital, is expected to be long and complex.
Some 150 witnesses are expected to appear.
India has the world's fastest growing mobile phone market, with more than 700 million subscribers.
If found guilty, the defendants could face a maximum sentence of life imprisonment.