Sources associated with the process said a team of officials from Vodafone, including legal, accounts, regulatory and international affairs, on Monday met Hutch-Essar officials in Mumbai to start due diligence on HEL's operations.

During the next four days, the 20-member Vodafone team will look into the top-line and earnings multiples of HEL along with the customer base and cash flow figures that has been told to Vodafone for the sale of Hong Kong-based Hutchison Whampoa's 67 per cent stake in HEL.

Vodafone is believed to have appointed Ernst & Young to help it conduct the due diligence.

Meanwhile, Vodafone CEO Arun Sarin was tipped to visit India during the due diligence process on January 10. But the Vodafone spokesperson in London neither confirmed nor denied media reports to this effect.

When asked about due diligence process having started, a Vodafone spokesperson declined to comment "at this point in time".  Meanwhile an HTIL spokesperson told PTI: "We don't comment on state of negotiations".

The process, which is expected to continue for another three to four days will see Vodafone officials getting access to the revenue multiples and Earnings Before Interest, Tax and Amortisation (EBIDTA) multiples. This will cover the expenditure, debt and interest of HEL.

Sources said Vodafone officials also will be told about the number of lost and dead connections of subscribers if any during the last few months ever since this news of Hutchison Telecom, the telecom holding company of Hutchison Whampoa, exiting India went out.

Vodafone will check the track record, customer base, churn, growth areas, number of towers among other operational aspects of the business of HEL.

"Vodafone will get an opportunity to check on those facts and figures of what has been been submitted to them by HTIL on HEL", sources said.

Sources also said the general due diligence process had started last week with officials of the British company meeting telecom ministry representatives last week, although they did not meet Telecom Minister Dayanidhi Maran.