They include a major-general responsible for evaluating defence procurements.
On Tuesday, the internet news site, Tehelka.com, revealed secret video footage showing senior politicians, bureaucrats and army officers taking money in connection with a fake defence deal.
The scandal has already forced the resignation of Bangaru Laxman, the president of the ruling Bharatiya Janata Party (BJP).
Parliament
Parliament was brought to a standstill on Wednesday after opposition MPs called for the government's resignation over the affair.
Officials were forced to adjourn sessions of the upper and lower houses until 2pm (0830 GMT) after the MPs chanted calls for Prime Minister Atal Behari Vajpayee to quit.
The main opposition Congress Party has urged the entire government to resign over the affair, and partners in the ruling coalition have called for an independent inquiry.
Mr Laxman, who said earlier there was "no question" of resigning, maintains he was a victim of a political conspiracy and that he accepted the money only for the party.
Another senior figure implicated is Jaya Jaitley, president of the Samata Party, which is a key member of the ruling coalition.
After an emergency cabinet meeting, the government said it was ready to investigate the allegations made by Tehelka.com.
Damning footage
The website said two of its journalists had posed as businessmen for a fake company, West End International, trying to sell fictitious hand-held thermal imaging devices to the Indian military.
They used hidden cameras to videotape politicians, bureaucrats and army officers accepting money.
In one of the most dramatic clips, Mr Laxman is shown taking a wad of currency notes and placing it next to him.
The incident comes amid court hearings into the Bofors arms scandal in the 1980s, in which a number of Indian politicians as well as businessmen are accused of taking bribes.
Commissions in defence deals are illegal in India.
'Concocted'
Mr Laxman, who became BJP president last year, said he had accepted 100,000 rupees ($2,170) as a donation for the party.
"As president I am not barred from taking funds for the party," he said.
He also said the two journalists had posed as traders, rather than arms dealers.
Another politician said to be implicated is Jaya Jaitley, the leader of the Samata Party and a key member of the BJP-led ruling coalition.
Prime Minister Vajpayee has so far refused to comment, saying he wanted to read the report by Tehelka.com.