India Oil Tanker Wagons
A file photograph of a worker walking atop a tanker wagon to check the freight level at an oil terminal on the outskirts of Kolkata, IndiaReuters

Seven people have been arrested in India on charges of corporate espionage, as official documents from the country's oil and natural gas ministry were stolen and sold to companies and energy consultants.

The latest among the detained are former journalist Santanu Saikia and another energy consultant Prayas Jain, according to media reports.

Saikia, who runs an energy portal named indianpetro.com, and Jain, who runs a New Delhi-based oil and gas firm, have been accused of buying the leaked documents, analysing them and selling them off to business houses.

Police also arrested an employee of oil major Reliance Industries, according to media reports. Reliance Industries shares fell as much as 3.4% following the news.

Four multi-tasking officials at the ministry have also been arrested in the case, according to the Times of India, which said more arrests are likely.

Raids have been conducted on the offices of oil firms such as Reliance Industries and Essar, and their staff are being interrogated, reports said.

Police earlier claimed that they received information about some people who were "trespassing" into ministry offices to steal documents. The people involved in the document theft allegedly used duplicate keys and fake identity cards and had passes to enter the oil ministry office.

Further investigation into the matter revealed that the stolen documents were sold to private energy consultants and those in the petrochemical or energy industry.

The documents reportedly contain sensitive information including policies on oil exploration, pricing and imports.

"The government will thoroughly investigate the nature of documents being leaked and the people who may have benefited from it and take tough action against them," Petroleum and Natural Gas Minister Dharmendra Pradhan said.